Yes, it is going to be a difficult task, I know :-( I'm thinking to strip the paint first, to make water penetrate into the wallpaper, then let the wallpaper soak, say, in hot water. The wallpaper is on the sheetrock. Do you think paint strippers like "Citristrip 1 qt. Safer Paint and Varnish Stripping Gel" from Home depot work fine and won't damage drywall? Any experience? Or better solutions?