I have read a couple of posts on here that state you can take tint off using a razor, windex, and a some heat. I went out a tried to remove the tint which the previous owner put on, but it just keeps tearing off in little pieces and I don't want to cut the defroster lines. Any suggestions?

 

Hot soapy water and a razor blade.
-P.

 

If it was cheap crap (which it sounds like it was) your only hope to not cut the defroster lines is to remove the film without leaving the glue behind. If it's flaking off, you're hosed.

I took my old car that had cheap tint on it to this place that has been around for about 20 years. They couldn't remove the glue without destroying the defroster since it had degraded to point where the film and glue were separating.

 

Ammonia in a spray bottle, spray the window and let soak for a minute. should peel off much easier, will work when trying not to damage the rear defrost.