I've been using a steamer the whole time but the thing came off in a million pieces.

Wax & grease remover, no go.

I would scrape it but the demister heater wires would get damaged if they aren't already.

Ill try warm soapy water.

Apparently if you rub it down with ammonia and let it 'bake' it comes right off.
How to Remove Tint Glue From Glass: 12 Steps - wikiHow

Bit late for that.

Heat gun might work.