Try a heat gun. Or try taking it to a car wash and power washing it. Either has worked for me. Depends on the paint.

If not, try acetone, which is a solvent for most, but not all, paints, and is pretty harmless stuff. Soak a rag and let it sit on an area for a while and penetrate. Epoxy paints, you might need a different solvent.

Sanding is a long, long way around.