How do I remove tint from a sliding gl door?

I just moved into a house. The house has been on the market for 2 years before I bought it. There is a sliding gl door in one of the rooms with this horrendous purple tint on it. I tried using a razor blade, and at first it came off in huge chunks, but now I've only removed 1/3 of it. all the pieces that come off now are tiny. I don't want to scratch the gl. Is there anything else I can use to remove the tint and the sticky adhesive underneath it?