There is an easier way, and faster too.
Remove the binder bolt from the frame, then drip some ammonia (REAL ammonia, not cleaner with ammonia in it) around the frame/seatpin area. Continue to drip in ammonia until it is fully saturated. Wait about an hour.
Keep the saddle mounted on the seatpin and use IT to twist the seatpin out rather than a wrench.
Once the seatpin is out make sure to wipe the ammonia from the frame and seatpin. When reinstalling use LITHIUM grease inside the frame rather than copper grease on the seatpin.