Do a quick search on this site and you’ll see all the options ranging from staples, thumb tacks, screw in buttons from an auto supply store, bows holding it up, or replacement. The foam backing deteriorates and separates from the cloth. There is no way to save it or reglue it. If you do it yourself, you can replace it for under $100. Matching material is available from Atrim.com or other. If you don’t want to replace it, one of the other methods to hold it up.