Originally Posted by jyasaki
Solvent and a scothbrite pad. For hypalon, MEK works best, I think. Acetone will work, but flashes off pretty quick.
Check in the SIB section; Peter_C has done this quite a bit.
The goal is remove as little material as possible yet all of the glue. Scotchbrite pads works awesome, but it takes some elbow grease. Use lots of MEK if it hypalon. Make sure to wear high quality neoprene gloves, and outside is the best location so you get fresh air. A good respirator is important too.
Some people like using drills and flap disks, but the pictures I have seen posted here show major material removal.
After glue removal you will need to scuff the now smooth material with sand paper or the proper type of file. A preprep wipe of MEK and you are ready to reglue.