Fill any household spray bottle with a mixture of 25% liquid fabric softener to 75% warm water. Make sure the nozzle is set to the "mist" setting. You can use any brand of fabric softener but you may want to use unscented if you don't want the room to smell like spilled perfume.
Spray the wallpaper with a liberal coating over one section of wallpaper. The fabric softener won't dry out as quickly as warm water would, giving ample time to fully remove a full section of wallpaper.
Wait a good three to five minutes and begin peeling off sections of wall paper from top to bottom. If there is still a paper layer remaining, repeat step 2 and peel off all existing wallpaper.