Sloppy painter some years ago go got paint on the brushed aluminum frame of the entrance doors at church and I want to remove it. I have available paint thiner, lacquer thinner and acetone. What will work, or something else ?

I'd try mineral spirits first, it won't flash off as fast as acetone or lacquer thinner. I've had good luck with soaking a heavy paper town and then laying it on the paint so it can soak in.