steam works best, and is the safest. rent a machine; for the few extra bucks it costs to rent, it will save you the agony of having to repair what was damaged taking the old stuff off other ways...
i have re-wallpapered a few kitchens and baths. it is a bit tricky, but once you get the "hang of it", it's not so bad. just remember to spackle and sand and prime the walls with special primer before you hang the new paper. and hanging the first sheet plumb and level is the key.
in nomine patri, et fili, et spiritus sancti.
Meh nom eh noh...doot dooooo do do do.