The best way make it wet enough to scrape off and score the wallpaper first. This is easily done with a utility knife. Once the wallpaper is properly scored, a chemical wallpaper remover will have to be applied. For own safety one can invest in some inexpensive safety glasses, rubber gloves and even a mask to breathe through. The removal agent can be applied with a paint brush, but this can take a while. If one don't prefer using chemicals they can use the much safer and environmentally sound wallpaper steamer method.