Just soak it with windex and scrape it with a new razor blade.
When you get down to just the glue, and no tint left, get a couple rags soaked with nail polish remover, and wipe it on the glue, it will scrape right off like butter.
Don’t get the remover on your paint, interior, etc.
I was able to do both windows on my truck in like 30 minutes this way.
Also had to do the tbird, when i got the tint ticketzzz…
Peel it off, then take the glue off with a soaked in windex #0000000 steel wool (the finest available) I’ve done it a lot of times, and it is the quickest. Try to go in the direction of the defroster lines when it comes to the back window.