Using a steamer should work well to get the paper off. Another trick I've also tried is to perforate the wallpaper.(There is a special tool to use for this that you can probably find at the local home improvement or paint store.) Then soak the walls with a solution of hot water and fabric softener - scrape off with putty knife. To remove the paste off the plaster (if there is any left) wash the walls with a solution of muriatic acid and water then rinse with fresh water. Or you can try just using bleach and water in the same way.