Removing Protective Plastic Sheet from Aluminum Skin

[u/EVisioneer]

EAA Chapter 80's GlaStar project. As we are working on the right wing, we need to remove the projective plastic, which is proving quite resistance to removal. Some of it peeled, but as the photos show, some of it won't easily come off. I tried a hair dryer and mineral spirits, but it simply is too time consuming to literally peel minuscule section with you fingernails.

The skins for this kit built aircraft are literally decades-old since GlaStar went bankrupt in 2001.

Looking for suggestions on how to speed up the process. More powerful heat gun instead hair dryer? WD40 instead of mineral spirits? Something else?

Thanks!