Door pin removal

I was told by bob burkitt how to remove my door pins to install a birch door.  He said that is the method Alex Birch taught him. 

Drill a hole in bottom of pin and use an air chisel.  

I have done a few this way now and so far have had 100% success.  

My door I had originally hit with hammers.   Had a friend bring a door pin remover tool. (Kept going cock-eyed)

The air chisel method popped the pin up instantly.