That old ancient paper was installed with something like wheat paste and/or celluose paste, so it should come off ok once you get it wet underneath.
I'd start at the top scoring the paper with a razor knife in a cris-cross pattern, mebbe one foot down, and work on getting that loose & away from the wall. Then just spray or brush a 50/50 mix of vinegar & water behind it and it should come loose & drop down via gravity.
The house I grew up in was built in 1909 and had multiple layers of paper on all the walls. The painters used a steamer that fogged up the room like a sauna. It was left on for 3 hours and the paper literaly fell off on it's own.