The simplest to cut lexan/polycarbonate/plexiglass is with a tin snips. It takes some hand muscles, but no sanding, no polishing. Just cut and done. If you can use a tin snips halfway decent, it looks like a factory edge. Been doing this for years with polycarbonate race car windshields. Buy a decent brand snips, like Wiss or similar. About $10-$15.
Btw, you can bend poly/lexan with a metal brake.