How do I remove wallpaper hung on unprimed drywall?

Steam might help, u can rent them...

Are you using anything to soften the adhesive? I use a 50/50 mix of vinegar and hot water in a spray botle. Saturate the wallpaper, let it sit, and scrape off with a putty knife. If doesn't want to come off at all that is the only time I recommend painting over it. Make sure you prime.

Here's an article that you might find helpful. http://smallnotebook.org/2011/09/02/how-to-remove-wallpaper-from-unprimed-drywall/

I've used a steamer for removing wallpaper.

Just did an entire room. Soak the wall paper with winded then you can scrape it off easily with a plastic kitchen spatula. The winded melts the adhesives and it rolls off the walls.

I have used a gel wallpaper remover, rolled it on and stuck a thin plastic drop cloth over it to really let it soak in, letting it sit for 1/2 hour or so. Keep a warm water spray bottle handy to keep it moist as you remover the paper. If it's a heavy vinyl paper you may need a paper tiger cutting tool that perforates the surface to let the remover through. Don't worry about getting the backing off with your first round. That will come off very easily just by wetting it.