Did you mean that you used a punch slightly SMALLER than the pin?I had to remove a pin similar in size to that from an older snowplow this past weekend. I used a large flat-face punch, that was just slightly larger than the pin. It was stubborn, but I kept hitting it from one end and then the other. It only moved about a quarter of an inch in each direction, but eventually, it did come out. I suggest that you work it from both ends using a properly sized drift pin. I don't think that heat is going to do much for you.
I have no way to get the tractor higher than the stabilizer will lift it so the bottom "hits" are not full strength, so to speak. The platform of the backhoe prevents access from the top so I can't get enough force to do anything from that direction either. And, this seems to be the major problem...there is no way to get to it. It appears that even if the backhoe is removed from the tractor, it would be difficult. I do not have the strength or tools to do much. Life is hard. :-(
Thanks for the suggestion, DustyRusty.
TG