The problem with vinyl is that it's nearly impossible to get the DIF solution back behind the vinyl to do its job. There are LOTS of posts on the Forum that talk about wallpaper removal. Use your Brower's FIND feature and look for the keyword wallpaper Don't stop at the first 'hit'. There are about 20 directly and indirectly related Posts on this subject.
One of my favorites is Wallpaper Removal. My best to ya and hope this helps. And don't stop at the one Post.