I give my snakes and reptiles steam baths..I get a container and put like an inch of water in it that's nice and warm, bot not hot, enough so it creates steam. I put a large rock or something for the snake to lay on if they don't want to be in the water. I put them in the container and pop the lid on and give them 5-10 minutes. It's usually really easy and the skin easily rubs off if it's ready to come off.

You can also put a himid hide in their tank and keep the over all humidity pretty high.