Make a mixture of equal parts warm water and vinegar and add two teaspoons of dish soap and put it into a spray bottle. Saturate the residual glue and allow it to sit for 10 minutes. Use a scraper to scrape away the now softened glue.
Place a half pound of dry ice on a metal tray and set it on the glue. Let it sit for about a minute and then move it to the next area. Scrape the newly frozen area with a scraper and keep moving the tray and scraping until all of the glue is gone.
Spray the adhesive with WD-40 and allow it to soak for about five minutes. The glue should come up easily when scraped with a scraper.
Scrape away as much glue as possible with a scraper and sweep away the residual with a broom or vacuum it up. Use a sander with 40-grit paper to remove the rest of it.
Use a heat gun or a hair dryer on the hot setting to heat the glue to where it is pliable enough to scrape away with a scraper.