I was replaying this and noticed there were unanswered questions in this thread, so here's my process.
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×1. Without killing the golem, lead the goblin to (32,17). You can go around the structure here without the goblin following you, giving you a chance to lead the golem to (31,19).
2. Now get the goblin to follow you from the west side, then go towards the tunnel. The golem will get stuck at (30,17). Go around the 3-by-3 square to lead the golem southeast of the closed door, then go for the tunnel.
3. Hit the lower-left orb. The golem will move and let you out. Immediately head back through the tunnel. Go towards (28,19).
4. When you reach (28,19), the roach should hit the lower pressure plate. Go around the east structure. At this point, the golem will be at (30,17) again.
5. Rush to the upper-right area and hit both orbs before the roach reaches the pressure plate.
6. Go through the tunnel and immediately go back once the goblin is south of the wall, so you can lead him to the pocket on the west side. Then go through again and lead the golem southeast of the closed door again.
7. Hit the northwest orb. The golem will, once again, let you out. Now just lead the goblin and then the golem to the newly-opened hot tile.