[Crazirich]

try a plastic razor blade first... less harmful than metal... and then you could use a solvent to get the glue off... don't bother with things like goo-gone its a waste of your time... you would need something more industrial... Hey brake cleaner may work... it works good on silicone, I just haven't tried it on tint. Just be careful not to get solvent or the glue all over your interior.

PS. Some tint companies (I don't agree with it) actually etch the glass a bit to get the tint to stick better....