It all depends how they were applied. The first thing is to get the sprayed on finish off if there is one. Either a mild paint stripper (dont let it soak through to the glass) or go ahead and sand. Once that is out of the way,they may come right up by peeing an edge, but if not water will help.Wet the skins with a sponge. They will eventually get damp and can be worked away from the limb a bit easier than when dry. The glue and part of the skin may remain, but you can at least see what your fighting. Tightbond can be scraped carefully with a flat razor picking most of it off. Other glues like goat tuff, etc. can be more difficult. Sand using different grits taking care not to penetrate into the glass.
Elbow grease and patience, I've had them come right off, and had to bust my cahones on others.
What kind of bow is it?