Don't knock yourself out with every bit of foam; you're going to recover it anyways.

What you want to do, is to get the heavy stuff off. You're going to have plenty of spaces where there was no glue on the underside of the hood, so you can apply your new 3M yellow or other stuff (there's a good generic at AutoZone, bigger tube for less, too), I had the toothpaste kind of stuff, smear it on, put your new pad in place, and that's it.

Bottom line, don't worry about scraping the old stuff off. Get the heavy stuff off, and recover.

jeff 1991 300d, 100k