Moving the Levers
You will need "Machine Oil" to be able to move the levers. You can purchase it from Ashk in Rahu. It also occasionally drops from mobs within the Sewer.
Lighting the Braziers
The outer braziers may be fueled by sacrificing a femur pile. The central brazier requires evil bones. Both drop within the dungeon. Once all braziers are lit, an "Enraged Spirit" will appear. Defeat him (remember to stun ghosts), to receive Velmer's Key.
Once you have retrieved the Lost Notebook for the Goblin Guard, you will be able to enter Chief Glortok's room. Within this room, talk to Stulza to receive a 30 minute +12 Accuracy buff.
Once you reach "Friends" favor with Bogaku, Chief Glortok will offer you quests.