yes, soapy water(in a squirt bottle) and a razor blade will take it off just fine. I'd suggest leaving the car in the sun for the day, and once it gets really toasty in there, start peeling the plastic off by hand.
For the rear window, peel all the plastic off slowly, you'll probably leave most of the glue on the window. Take some 00 steel wool (get it from Home Depot in their paint section) and with a lot of soapy water sprayed on the window, start scrubbing lightly. The glue will come off but not the rear defroster grid.
Enjoy, its a stinky, dirty, aggravating job-I know, I tinted for a shop in Des Moines for a year (and several prior years back home in Honolulu) before I lost my mind!!! :shock:
Chris