Hello all, I've been rebuilding a 71' Starcraft Chieftain for the last year and am now replacing some Plexiglas. I bought the plexi last year and did not remove blue protective film, it is now very stuck on. After looking around various forums I've tried several methods to remove the film; heating, wd40 and a plastic putty knife, VM&P naphtha and a putty knife. All have had almost no effect and the putty knife is definitely scratching the plexi. I have not worked with plexi before this, but i'm assuming i could sand it and polish it clear again? Any knowledge on the subject would be appreciated, thanks.