DD motorbox insulation

[Badgerski51]

Ok, not sure if this has been covered or not. I didn’t see it in anything I found. I’m about to insulate the motorbox cover. There’s a very thin foam type film lining most of the inside. What’s the best way to take it off so the new insulation has a good surface to adhere to? Heat gun and a scraper? Or some kind of chemical removal? Thanks

[formulaben]

If the old insulation was applied with adhesive I'd use Sentinel 747 Adhesive Remover.  Let it soak in, give it time and it does all the work.  I used mineral spirits to clean off the glue/adhesive remover residue, then acetone afterward, and then Windex as a final cleaner to prep the surface for adhesives (GatorStep) when I used it.