I am in the process of doing the exact same thing!! I was using a sander with 50 grit sandpaper, but this was just melting the paint into the floor. I am actually on my way to walmart to get some paint stripper and see if that works at all...I only have a few places where I'll have to do it. I read in another forum that this is the only way to do it, just apply the stripper, wait a while and then scrape it off; the lady suggested reusing the stripper. I'll let you know hoe it goes.