Don't make it complicated - peel off as much as you can with your fingers or a PLASTIC scraper - a little WD-40 on a rag as MIDLo suggested, just rub the area, and all the adhesive 'boogers' will wipe off.
Works good on bumpers stickers too - PB+J and hair dryers, etc may all work, but too much effort.
This method is easy and gauranteed to work