Also would be a good idea to spray some PB-Blaster onto the wedge. Remove the bolt completely and put the spray-straw up though the wedge's hole from the bottom and spray liberally. Also spray some down from the top in the gap between the steerer-tube and stem's quill. Let sit overnight.

I've had some severely corroded and stuck seatposts that I couldn't force free with gorilla force on the seat. Even bent the seat-rails in the attempt. Sprayed some PB-Blaster on it and let sit overnight. In the morning, the previously frozen seatpost had sunken all the way down into the seattube from just the weight of the seat.