There is no good way to do it, it's a long messy job. The glue is good up over 200 degrees, so the hair dryer won't touch it. An industrial heat gun would probably be your best bet. Mineral spirits or Xylol (a better quality & more expensive version of mineral spirits) is the solvent for most contact adhesives.
Is it so damaged that you can't just go over it or dye it the color you want?
No one lives forever, the trick is creating something that will.