The pin is a press fit, so you can either drill it out, heat the protruding piece with a torch and pull it out with vise grips, or just drill another hole beside it and drive in an appropriate-sized pin. A small fraction of an inch difference in location isn't going to make a noticeable difference in the way the heat riser operates.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!