Carbon fiber, a hammer and a chisel are never a good combination but sometimes you just gotta do what you gotta do. A carbon seat post had fused itself inside the seat tube of my Felt. I tried everything I could think of to free the stuck post but nothing would budge it. I finally cut it off just above the top of the tube. I used a hacksaw blade to cut grooves inside the post. I then spent two hours carefully chiseling the seat post from the aluminium insert that sits inside the seat tube. Finally, I had success with no apparent damage to the frame.