Any tips for removing the film off of old metal panels?

Blue film protective adhesive on 24 ga. metal roof.

I have 2000 sq. ft. of 24 ga. brown painted 12" wide metal roofing with 1-1/8" standing seams that has been sitting out in the sun for about 3 years or more and the film is now extremely difficult to remove. Do you know of any practical way of removing all this film??   Paul Penkala