[Richard]

Hmmmmmmmmmm,

I have had really good luck with 3M adhesive remover. Soak, and scrape with a putty knife. Worked better than anything I have tried including wire brush on side grinder, air chisel, razor scraper, and a good talkin to.

The key is to keep the working edge wet with the adhesive remover.

By the way, thanks to a tech at Newell for this trick. He saw me struggling to reskin a bay door. He came back with a spraycan of the 3M. I couldn't believe how well it worked.