Go to the hardware store and get a a tool called a “Paper Tiger” it is a tool to score holes in the paper to absorb water and chemicals. Then get a good sized spray bottle. Big enough to hold plent of water but small enought to comfortably hold in your hands. Get a product called “Dif” It is a chemical that will losen the glue. Sometimes just hot water works. You will need a type of scraper called a wallpaper scraper. It is bascally a long razor blade ( be very careful as it is very very very sharp).
Use the paper tiger to score holes in the wallpaper. Don’t press too hard or you will need to use spackling the repair the holes in the drywall. The holes however may be unavoidable. So it would be a good idea to get some drywall spackling.
You will also need a five gallon bucket.
In a five gallon bucket put in very hot water. As hot as you can get from the faucet. Then add some of the Dif. In the Spray bottle put hot water(as hot as possible from the faucet) and add some Dif. Shake the bottle to mixe the chemical.
S[ray the walls with water and allow to soak. Do this about 3 times and make sure you soak the wallpaper generously. Start removing the wallpaper with the scraper. Start at the seams as this will be easier. The wallpaper should remove easily if the wallpaper was hung properly. If not hung properly you might have one heck of a job in front of you
Sometimes you can remove the decorated layer of the wallpaper by hand or with the scraper without wetting it. Then you can wet the backing and that will be easier.
After the wallpaper is removed clean the walls to remove all the glue and then let it dry. Repair any drywall/Plaster damage. Prime the walls with a quality primer. You may have to prime the ceiling as well if the removal process damaged the ceiling.