Press the buttons on the lower rim to summon fireballs. Then, hit the machine in the center with everything you've got!
The boss has 3 stages. In each stage you must destroy the glowstone block.
   Stage 1 - The glowstone block is fairly unguarded. Just break through the thin layer of glass to hit it.
   Stage 2 - The glowstone block is surrounded by more blocks. It may be harder to hit.
   Stage 3 - The machine starts shooting fireballs back at you, destroying ladders!
	     It also breaks parts of the lower rim, making it harder to get to the buttons.
Once the glowstone is broken for a third time, the machine will explode and a passageway in the back of the chamber will open.