Toilets, Sinks, Showers, Tubs and Disposals - bathroom sink drain pipe removal

I am replacing the brass coated popup and flange on a kohler drain assembly and can't get the flange assembly loose from the drain pipe. It should unscrew but it won't budge. It was installed about 12 years ago. Any ideas?
Thanks:madhell:

If you are talking about the flange part that is above at the bottom of the sink bowl, did you get the drain loose yet? If the drain is loose, and you no longer need the flange or drain pieces, carefully use a hacksaw blade to cut the inside of the flange and that should loosen it up. Sometimes you can take 2 pair or vice grips and clamp on opposite sides of the flange, put a large screwdriver between them and while you or someone else is holding the bottom part, try loosening the flange piece now.

If it is the bottom nut you cannot get loose, use a drill with a 1/4" metal bit and carefully drill into the nut a few times, then with a screwdriver, pop the nut apart.

If nothing here can help you please elaborate.