Not sure, I luckily have not had happen, and my cameras are so far trouble free. I am guessing if you remove the bottom plate, or maybe the top plate you can see where its jammed up. What I have read online says its only a few screws, and a locking collar ring around the wind lever thats holding the top plate on.

If anyone has a copy of the repair/service manual I would love to have a copy, just in case.