[Closed] Carbon frame/ alloy seat post

WD40, old saddle, freeze the seatpost, twist. There is no chemical bond, just surface corrosion of the seatpost.

Had the reverse; carbon post in a steel frame. Hot water on the frame replaced cooling the seatpost and it came free. Will need a good soaking of WD40, so be patient.

I cut mine out with a hacksaw, cut post 2 inches above frame and then cut at an angle downwards into the slot in the frame and continue the cut downwards using just the blade. Take care not to cut into frame and once you've cut through you can squeeze the post and this should free it from the frame.