For the best protection of your walls, I would suggest having a professional remove the wallpaper. However, here are the basics. Applying HOT water along with a solution called Dif will allow for removal. When wallpaper becomes wet enough, the adhesive will soften and the wallpaper will release (maybe with some help). I have found that using a pump up garden sprayer works best for wetting the wallpaper. Add the Dif to the sprayer along with the hottest water you have. Pump up the sprayer and wet the surface. (WARNING, water and electricity don’t mix so cut off the breaker in the panel box to avoid shock or fire.) Some wallpapers receive water and are saturated quickly. Others may repel the water.
Determining how wallpapers may react to removal.
1. Fabric back vinyl, lift a corner and gently pull off of the wallpaper at a 45 degree angle.
2. Uncoated Wallpaper, wet multiply times as described above then remove.
3. Vinyl protected front/paper-backed wallpaper, the front needs to be removed first, then the paper backing. Try lifting the vinyl front and pulling it off. It may come as an entire piece. If not, then a razor scraper will remove the vinyl front. After the vinyl front is removed the wet the paper backing and scrape off.
4. Non woven papers, lift a corner and pull at a 45-degree angle.
5. Grass Cloths, wet with water and the woven front will remove first. Then rewet the paper backing and scrape off.
6. On wallpapers where water penetration is slow, sand the surface with sandpaper to break through the protective coating.