Having the wallpaper applied directly to drywall, I don't think there is any 'easy' way to remove it. When I did my living room last year, I had the same problem. Found it just as easy to remove it using a scraper with a razor blade in it. Took a few times to find the right angle for the blade, but once I did, most of the wallpaper was removed without a large number of gouges in the wall. But like any method, it takes time. And LOTS and LOTS of patience. LOL
I tried Diff, and I thought it sucked. On 'normal' walls, I've had much greater results using a half and half mixture of vinegar and water. If you can peel off the top layer of decorative paper, while leaving the underpaper with adhesive, even better. Spray with mixture, let sit for 5-10 minutes, peel.
If scoring through the decorative paper is necessary, spray mixture as well, and liberally. I've also found that so called wallpaper scrapers are just about useless. My favorite tool for wallpaper stripping became a 4" putty knife.
If I hear some faint cursing and swearing, I'll know where it's coming from.
"Can you hear me now?"
"Why, YES, I can, but it wouldn't be proper to repeat it."