It was easy* to cheese if you go through the caves. Spawn at either of the first two lamps (I used the second one), down the ladder in the Well, which prompts the first guy to start patrolling.
Go back up the ladder, run past everyone (or methodically kill a few of the easier ones), and get ot the last lantern.
Go down the elevator, kill (iirc) two Singing Brain Dudes.
Stand toward the edge and shoot at the patrolling guy until he agros you. These guys are tall enough that most ground slams (Kirk, LHB, etc) will hit them as they clip through the ground. Carefully chip away at them until dead. You can also just hit them ranged if you have a good enough weapon, I suppose.
After numerous tries, I was able to kill them with this method on my very first attempt.
*When I say easy, I mean it's a more consistent method with lower risk for getting dicked.
