Stripping it off will be either easy or painful depending on who hung the paper and with what. If a pro did it? The walls were primed and sized. You will have no major trouble getting it off.
Buy a paper scoring tool at the paint store. Spend millions on commercial paper removal products or mix fabric softener and warm water. Do not saturate so you hurt the wall, but soak the paper and then strip it off with a nice thin drywall knife. If it is modern wallpaper, and you give the mixture time to saturate, it should fall off in giant sheets.
I work on antique houses and often encounter layers of paper. I have never found a better way yet then steaming through the layers and patiently getting the paper held in place with MY Friend Flicka glue remains in place.
I do enough of this that I own a nice wallpaper steamer but you can rent one for chimp change I should think. Hate to hear myself saying this but the box stores sell a Wagner toy for like $49. It might work for one bathroom? A day rental of a real steamer would cost less than that I hope.
Even trailer trash people and Al Bundy shoe saleman types know better than to paint over wallpaper by the way