I recently had to do this.
On the side windows proceed as follows:
1. Cover inside of door with trash bag so little bits of glue don't gunk up the interior.
2. Peel the tint off. With luck and by going slow you can get it to take most of the glue with it. I found that heating it actually made the glue stay with the glass. I'd recommend avoiding heat but YMMV.
3. Spray with Windex/scrape with razor, wipe glue off razor with rag, repeat until clean.
The first window will take you 15-20 minutes until you get the hang of it, the remaining 3 will take about 5 each.
On the rear window:
1. Spray with water on the outside and test defroster to see if all the wires actually work. This will make you feel better afterwords as you'll know you weren't responsible for all of those broken defroster wires.
2. Cover interior.
2. Peel.
3. Windex and 0000 steel wool. Rub in the direction of the defroster wires. You will use a lot of steel wool as it gets gummed up.
Good luck!