I've been there before, it's not fun! My Escort had tinted windows when I got it that were 70% visibility in the front and 30% in the back, it all had to be removed.
I also had this happen in the cold part of the year. Getting the tint warmed up will make a huge difference. Use a heat gun, hair dryer, halogen floodlight, or whatever else you have at your disposal to heat it up. Not to the point that it's melting, just so that it's warm to the touch, it'll really soften up the adhesive. When I removed mine I used a plastic paint scraper from the hardware store, because with the razor you run the risk of it etching into the window. It doesn't work as well as a metal blade but its impossible to scratch your glass with one.
You can also buy something called tint-off that comes in a small spray bottle. I got it at wally world right next to the window tint rolls, you can probably buy it almost anywhere. I would work on a corner of the window, then spray this stuff in between the window and tint film, then work on a different area of the window while that worked itself in for a couple minutes, spray the other part, then go back to the first section and scrape some more. The tint-off helps to loosen up the adhesive and when you're done spray some more on a rag to get the rest of the residue off, it'll work a lot better than regular glass cleaner and it's not going to harm the door panel or anything else.
So you don't have to remove it from the back windows? The policeman made me remove it from all the windows although the way I interpret the law here in PA, he was wrong and I should have only needed to remove mine from the front doors. The hatch window was the real nightmare, because of the traces for the window defroster. I was careful to work between them and around them, and I still ended up ruining all but 2 lines towards the top of the window, so that really rendered the defroster useless.