The black adhesive needed to come off the concrete. We decided that this was the perfect DIY project. Home Depot had the special chemical to remove this type of adhesive. Gloves, Mask, Floor Scraper, Hard Bristle Broom, Floor Squeegee and Dry Powder. It took Jonathan about 2-days to complete the job (220 sf). It came out really-really good!!! Even to Jon's standards.
(I better say that... He's the one that did the job.)