They have products you can buy that dissolves the window tinting. You can find them on Amazon.
Inspection window sticker remover. Get a piece away from glass and add some winded and let it soak.
If will depend on what application method was used.
Hi Bob. Boy, I had this chore. It was a great idea from the previous owner but I couldn't stand the blue effect when I looked out. I used marine paint remover. It was the only thing I could find that would work. The hardware store products just didn't take off this very thick film. If you go this route, wear gloves, old clothes and ventilate the room well. Good luck!