So how do I get the other two goblins out of here?

Hint 1 of 7:

Did you notice that the floorboards on the platform look a little loose?

Hint 2 of 7:

The one on the right side in the foreground is.

Hint 3 of 7:

Did you notice anything above the floorboard that could help you?

Hint 4 of 7:

The rocks up there also look a little loose.