Well I was just out in the garage giving this a try.
I used a single edged razor blade and I put two wraps of masking tape around the ends/corners.
So the blade can basically slide on the surface riding on the masking tape, the blade in the center scrapeing the run.
Works pretty good, but I noticed the deeper you go into the run it was still a little soft so I stopped and I'll continue in a day or two. Got about 1/2 the thickness of the runs off.
Thats pretty nerve racking though, scrapeing a razor blade across a brand new paint job but it seems to be working.
Thanks for the tips everyone.