I dunno about lens removal. I've head it takes about 450 degrees Fahrenheit(spelling?) to get the clue to melt. As for getting the scratches off. wet-sand the lens with 1500, then 2000 grit sandpaper, then get a polishing compound, the kind for clear-coat paint, and use that. Mine came out pretty well!
I should add that I got over the whole clear corner/altezza thing a while ago... just an old picture.