How to Take Off Wallpaper from Drywall by Soaking and Scraping
Soak the surface with a wallpaper removal solution.
Although a paintbrush works, the most effective way to get the solution on the wall and not all over the floor is to use a paint roller or a spray bottle.
Warning: Don’t wet an area larger than you can scrape off within about 15 minutes. If the drywall soaks longer than that, it may cause unnecessary damage.