Removing auto paint from concrete floor

[BTL-A4]

I'm finishing up painting a car with single stage urethane paint. I did not cover the floor. What is the best way to clean the paint off?
If I use a solvent, I'm concerned about fumes. I can wear a respirator, but I need to remove the solvent and paint correctly; I don't want to just wash it in the gutter.
I tried scraping and got some off, but there is still some left. The area with paint is about 16' x 18'.
Should I rent a floor polisher or scraper?
I'd appreciate any advice from anyone who has done this. Thanks!

 

[The Cobbler]

probably need to grind it with a diamond wheel .

 

[BTL-A4]

Would I use a hand grinder or rent some sort of floor grinding machine?

 

[Matti]

Adhesion is probably not great. I'd try a pressure washer or maybe a pressure washer sandblaster if that doesn't work.

 

[James-W]

Maybe this is a dumb idea, but perhaps a floor buffer with a "wire brush" type pad or a sandpaper pad would work. As has been mentioned, a diamond grinding brush on a floor buffer would do it too. If it were me, I would try the wire brush and/or the sandpaper pad first though.