One of the methods I like to use is the “contractor” method, if possible. It does cost a little more....but it’s very easy, doesn’t take a lot of work, and less time consuming. 
For sho! Next time I'm using the contractor method!

My hands felt like they were going to fall off! Behind each wallpaper were many layers of yuck that I had to take off. The wallpaper itself, then the dried up and hard glue, then the soap that washed off that glue. Also, sometimes when you rip off the wallpaper, that process can remove some of the old paint and drywall, so then you need to use the drywall patching mud (I used the Ready Patch mud that's already made so you don't have to mix your own mud) to fill in those little holes and then smooth out the mud with a putty knife, then you need to let the mud dry, and then sand down the dry mud to create a smooth and even surface before painting. It took me FOREVER (a week) to take down wallpaper from approximately 20 walls and to get the walls cleaned before they could be ready to be repainted. I hate wallpaper! Please, never put up wallpaper, everyone! I beg you!
The best way to take down wallpaper is to do the following:1. Combine hot tap water and Dawn dish detergent in a sprayer bottle. Note: Don't use a lot of soap; fill the bottle up with hot tap water (don't use boiled water) and put in about a teaspoon of Dawn dish detergent.
2. Take off the wallpaper from the walls.
3. Spray the hot water/dish detergent mixture on the the small areas of the wall that you'll be working in for approximately 2-4 minutes at a time; let the water/soap mixture soak on the wall for 1-2 minutes before you use a putty knife to scrape off the glue.
4. Repeat step 3 on the other parts of the wall until you've removed the 1st layer of glue from the wall.
5. Wet a dish washing scrub sponge (the ones with a scouring side) in hot water with dish detergent and remove the excess glue off the walls. Use the scouring side to remove the glue and the soft spongy side to wipe off the glue.