I used a razor to pull up the corners where my fingers couldn't fit, then i peeled it all off. Mine was easy and came right off. when i had some glue, i just used amonia, and it came right off.[/QUOTE
+1
I used a razor to get the corners started then used goo-gone to remove the glue. Additionally, you could try a tint shop to find out what they use or what they charge.
Laurence