How to Take Off Wallpaper from Plaster with a Wallpaper Steamer
Buy or rent a wallpaper steamer.
You can rent a wallpaper steamer (for about $15 for a half-day). But if you have a fixer-upper, it would be worth your while to buy a do-it-yourself model (about $50).
When you use a steamer, be sure to take every precaution to prepare your room for the moisture to come.