Well that wasn't too bad. After pulling the rest of the posthead off, I used my big bolt cutters to cut a couple stress risers into post. If they had small jaws, I'd have gone ahead and cut slots. Or if I wasn't feeling lazy I'd have cut slots, but flattening a seatpost is pretty easy either way when you have a nice big bench vise and a long enough cheater. Once I had it flattened out enough to hold fast, I was able to twist the frame free.
