Wow, piece of cake. Had some nearly 20 yr old tint on my TL that had turned purple and basically peeled off. I was left with a cloudy film on the rear window.

Fired up the garment steamer and it allowed me to peel it off quite easily. Followed up with some Acetone on a rag to remove any remaining glue. Miss the tint but it was getting tough to see out the window​​​.

 

Get some new tint brotha!

 

Another process I use are garbage trash bags and windex. Spray windex onto the window and cover the whole area using the trash bag and let it bake outside the sun for 20 minutes. Within the 20 minute time frame keep on spraying windex and cover up the area again. Do that process 3-4 times. Then take out the trash bag and the glue from the tint will stay onto the tint. This process is good for either the front windshield or rear windshield. Back windshield is good because of the defroster line. Process is slow than using the steamer but you get a cleaner job.