The one time I had to remove tint I sprayed the glue with Simple Green and just kept rubbing with a old terry towel. Once the glue was gone which seemed to take forever I washed the windows as usual. Hopefully someone else will have a quicker solution.
Have you tried Goo-Gone? It removes the adhesive residue from the paint of my new car (Autopian style, no dealer prep) safely and quickly. I can't imagine it would hurt the defrost lines.
windex with a single edge razor blade. Never have had problems witht he defroster lines, just dont use the blade to cut. I use it in an almost parallel possition to the glass.