I'm with Biscuitqueen. There is a scraper ball kind of thing you use to remove old wallpaper. It scores that plastic film so the spray remover can be absorbed and permeates to soften the glue on the back. It has to be soaked pretty good once the plastic film is scored, but you just keep watching it - it should darken some if the liquid is permeating it. Now that I'm older though, I hate messing with all that. I would sand the wall some, apply some kills (white paint with built in primer) then a satin paint. After that, it will take any treatment you want to apply.