I used a heat gun at first, but then just used the afternoon sun. I used a plastic scraper some, but mostly just my fingers. It was a process spread over a few months. When the fingers got sore/tender I would quit and come back another day. After I cleared an area I used GooGone to remove the adhesive much like jacwjames describes using gasoline. GooGone smells much better!!! I would spray it on the surface, then spray some on a paper towel and lay it on the surface, wipe off & repeat.
I first tried some expensive stuff called Vinyl Off apparently used for vinyl wraps, but it didn't have much effect.
I really cringe at the idea of using gasoline. It no doubt works, but can damage paint and hands in addition to be quite flammable!
If you want to use something petroleum based I would try WD-40 first … handy spray can and far less caustic than gasoline. You would be surprised at everything that WD-40 can be used for!!
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Paul (KE5LXU) ...was fulltimin', now parttimin'
2022 Coachmen Leprechaun 319MB
towing 2017 Jeep Grand Cherokee Limited