get yourself a commercial steamer !! I bought a rental unit at the depot.. Can't live with out it... I did a fleet of vehicles that all had lettering, and tried everything, this worked the best! Rent one and give it a try.. You will end up buying one like I did. If their is any glue residue left over go to the paint isle and buy M.E.K. it dissolves the existing glue. Nothing will work better!