Special thanks to @mightyphred, @Grimris, @Shannah and @Sellena for help with this guide.
This is a guide for the 3 item set (Explorer's Kit) and an additional 2 item jewellery set which is one of three variants (Tough, Eager or Avid Explorer's Kit) each of which provides a different set bonus.
DO NOT destroy the items from the 3 item set when you level out of T2 as they will be able to be upgraded in T3 but this is not yet implemented.
Order
High Elf
BOOK UPGRADE - See The Book of BOOM II
ORB UPGRADE - Lessons of the Past, Chapter 5, The Shadowlands (62k, 15k)
The quest giver is the vendor for the upgrade, Urien Longtear, Shadowlands, Chapter 5. After you hand in and get the next quest from Urien, you need to find the Alter of Yenlui (54k, 13k) and finally kill a normal level 12 mob to complete the quest.
BAND UPGRADE - Aethyr Essence, Chapter 7, The Shadowlands (58k, 55k)
Head to Shadowlands and go south to find the Dead Archmage. You will need to finish a PQ to get the upgrade item. The quest giver is the vendor for the upgrade Thaewyn Fairwind, Shadowlands, Chapter 7.
2-Piece Bonus Explorer Kit sets
You need to collect all these items then head to the vendor to buy a necklace and a ring from the same set to get a variety of bonuses. Choose wisely!
Shard of Galri - Nagarythe Statue Plaque, Chapter 5, Shadowlands (46k, 13.5k).
Spiny Spider Parts - Thana Soreyn, Chapter 6, Shadowlands (44k, 24k).
Ethereal Tooth - Endriol Slendervale, Chapter 7, Shadowlands (55k, 52k)
Raven's Feather - Wounded Elf, Chapter 8, Ellyrion (46.5k, 13k).
Dandalia's Star-Shaped Locket - Loose Rubble, Chapter 9, Ellyrion (33k, 45k).
Merchant location: Lorekeeper Naerelle Chapter 9.
Dwarf
BOOK UPGRADE - See The Book of BOOM II
MUG UPGRADE - Barak Weald Hops, Chapter 7, Barak Varr (62k, 40k)
The merchant is the quest given in Chapter 7, Brewmaster Furd
BAND UPGRADE - Forge Spark, Chapter 5 (8k, 27k)
The merchant is the quest giver in Chapter 5, Dwinbar Kazran
2-Piece Bonus Explorer Kit sets
You need to collect all these items then head to the vendor to buy a necklace and a ring from the same set to get a variety of bonuses. Choose wisely!
Rune of the Oathtaker - Unfortunate Dwarf, Chapter 6, Marshes of Madness (2k, 11.5k). Go into the Mourkain Tomb cave and head to the further west part.
Glowing Spirit Essence - Wynyssa, Chapter 6, Marshes of Madness (19k, 14.5k)
Furgil's Empty Keg - Furgil Brewerson, Chapter 7, Barak Varr (61.5k, 52.5k)
Tome of Dark Rituals - Undisturbed Skeleton, Chapter 8, Marshes of Madness (39k, 17.5k)
Lump of Oathgold - Gold Nugget, Chapter 9, Marshes of Madness (50.5k, 47.5k)
Merchant location: Felmi Mirnissdottir, Chapter 9, Marshes of Madness.
Empire
BOOK UPGRADE - See The Book of BOOM II
RING UPGRADE - Aqshy Essence, Chapter 5, Troll Country (18k, 40k)
Fly to Troll Country then head into chapter 5. Skirt the edge of the PQ until you find a large tree and click on the Firehardened Clay Jar. Then head directly north, the NPC you need to find will appear on your map as you get close (17k, 33.5k). Then the final part will be to complete the PQ you are near.
RING UPGRADE - Blessed Wax, Chapter 7 camp, Ostland (50k, 250).
Fly to Troll Country and run east, look for a line of troops then the piece of paper, Templar Decree, on a box in front of them. Next, fly to from Chapter 7 flight master to TC then fly back to Ostland to fast travel to chapter 8 where the next step in the quest is. Run to the houses to the west and you will find chests to open. When you work your way through them, the last one is the suspect belongings and spawns a normal level 15 mob to kill. Then return to hand in to the Templar to complete.
2-Piece Bonus Explorer Kit sets
You need to collect all these items then head to the vendor to buy a necklace and a ring from the same set to get a variety of bonuses. Choose wisely!
Patch of Blight Thorn - Blight Thorn , Chapter 5, Troll Country (18.5k, 35k)
Token of Ulric - Shrine to Ulric, Chapter 6, Troll Country (43.5k, 46k)
Donatelli Family Plowbalde - Empire Plough, Chapter 7, Ostland (45k, 20.5k)
Ol' Man's Golden Tooth - Roland Steinhauer, Chapter 8, Ostland (31k, 21.5k)
Strange Warts - Artyom Dannenberg, Chapter 9, Ostland (39k, 58k)
Merchant location: Karl Feinburg Chapter 9.
Destruction
Dark Elf
BOOK UPGRADE - See The Book of BOOM II
IMPLEMENTS UPGRADE - Flayer's Friend
Fly to the Shadowlands head far north to the PQ Rock of Galirian and in a small pool you will find a body (23k, 4k). Click it to start a short quest.
You need to find a rope on the boat directly north then go south to below the cliff segment (25k, 6k), you need to target the rock on the cliff and click the rope in your bag.
When you do this, click the rock again to complete the quest and you will be ported onto the cliff. Go to the other side to find a fireplace. Click it and it will tell you to head north-west to find another clue. Go to the islands just off the shore (17.5k, 2k) to find another fireplace, click it and a mob will spawn, kill him to complete. Hand in at Chapter 5 and the NPC you hand the quest in is also the merchant to upgrade your Implements Jewellery.
BAND UPGRADE - Dhar Essence
Fly to the Shadowlands and head directly west until you find a Hysh Crystal (3.6k, 51.8k). You will need to head to Chapter 7 to get the next step which is to complete the Griffon Gate PQ to get the upgrade item. The quest giver is also the merchant to upgrade your ring.
2-Piece Bonus Explorer Kit sets
You need to collect all these items then head to the vendor to buy a necklace and a ring from the same set to get a variety of bonuses. Choose wisely!
Queen's Codex - Ruined Chest, Chapter 5, The Shadowlands (33.5k, 4k) - Click the book you get in your Quest inventory once you click the Chest.
Battered Amulet - Preserved Skeleton , Chapter 6, The Shadowlands (15.5k, 13k). You need to jump up on the ledge from the other side before you can walk round to the skeleton.
Unicorn Horn - Unconscious Warrior , Chapter 7, The Shadowlands (22k, 58.5k)
Filled Flask - Stout Skeleton, Ellryion (22k, 23.5k)
Scout's Satchel - Dead Body, Ellryion (8k, 48k)
Merchant location - Relic-Hunter Eryminx, Ellyrion, Chapter 9 (15.5k, 36.5k)
Greenskin
BOOK UPGRADE - See The Book of BOOM II
BAND UPGRADE - WAAAGH Essence, Chapter 5, Barak Varr (10.5k, 33.5k)
GOURD UPGRADE - Ripe Tripe, Chapter 7, Barak Varr (54k, 42k). The ogre quest giver in the Chapter 7 camp is the merchant to upgrade your gourd. When you do the quest with getting water from the cave, you need to stand on the bridge where you cannot see the bottom either side and click the bucket in your inventory.
2-Piece Bonus Explorer Kit sets
You need to collect all these items then head to the vendor to buy a necklace and a ring from the same set to get a variety of bonuses. Choose wisely!
Soggy Stunty Beard - Waterlogged Dwarf, Chapter 5, Barak Varr (3.5k, 18.5k)
Throcane Bone Shard - Vileman's Body, Chapter 6, Marshes of Madness (15k, 8k)
Seagull Egg - Seagull Egg nest, Chapter 7, Barak Varr (63k, 36k)
Quid's Shiny Fing - Salty Beard Barrel, Chapter 8, Barak Varr (53.5k, 21k)
Salamander Egg - Half-Submerged Egg, Chapter 9, Barak Varr (15.5k, 13.5k) - you have to keep clicking it until it lets you loot it, it is a bit buggy.
Merchant location - Huglob Da Finda, Barak Varr, Chapter 9 (28k, 18.5k)
Chaos
BOOK UPGRADE - See The Book of BOOM II
EYE UPGRADE - Seer's Eye
Fly to Ostland and head to Chapter 7. The item is inside a tent. You then have a short quest chain to first kill a wolf inside the marked quest area, then fly to Troll Country and complete a murder!
BAND UPGRADE - Chaotic Essence
Fly to Ostland or Troll Country and run down to a group of tents across the river at 8.5k, 7.5k. In one of the tents you will find an Ostland Militia Crate to click and start the quest. Run down to Chapter 5 to hand in and get the next step to complete a PQ to get the Upgrade item. The quest giver Decasor En'Trio, is the merchant you need to upgrade the band. The ring will need to be unequipped and in your bag.
2-Piece Bonus Explorer Kit sets
You need to collect all these items then head to the vendor to buy a necklace and a ring from the same set to get a variety of bonuses. Choose wisely!
Congealed Blood Drops - Broken Barrel, Chapter 6, Ostland (12k, 600). Fly to TC and run south
Precious Ambergris Coated Coins, Putrid Corpse, Chapter 5, Ostland (11k, 22k)
Shijjirian Fang - Widow's Arch, Chapter 7, Ostland (61k, 9k). Click the gate, kill the spider that spawns and click the item in your Quest Inventory to get the fang
Daemonette Action Figurine - Lars the Incarnate, Troll Country (Chapter 8 Camp). NPC is to the south and has a quest.
Dwarven Trollslayer' Axe - Trollslayer's corpse, Troll Country (9k, 8.5k). The NPC Fishy Gnoblar is in this area which is the starting quest given for The Book of BOOM II.
Merchant location - Zenja Traugut, Troll Country Chapter 9 (56.5k, 17.5k)
