One method that I often use is using a soaking wet pillow case. Just place the snake in a warm, wet pillowcase and twist off the top. Then place the bag in her cage away from a direct heat source. You can keep her there for up to two hours, but you probably don't need longer than 10-20 minutes. The eyecap and any unshed skin will moisten and should come off as she moves around the bag.

Good luck!