The first thing I would try is this:

Take an old saddle you care nothing about and install it on the post. Hit the nose of the saddle with a hammer, first one side, then the other, in hopes that the post will come loose. Repeat as necessary.

Keep in mind, if you get too agressive with the hammer, you'll not only ruin the saddle, but possibly damage the seatpost. But this method has always worked for me, and I feel fortunate that I've never worked on a seatpost that was stuck so badly I had to use chemicals, hacksaws, etc.-