Whoa, hang on here a minute. That stud is probably swedged from the outside. I think all of them are on 62-64 cars. You can punch it out outside to inside, but that swedge will make it extremly difficult with a hammer. Its hard to do it with a press, which may rip out more hole than you want to. Anytime I have taken them off I have either drilled the stud head off, or ground it off. If the drum is not loose on the hub, its because of the swedge. You might want to re-think the hammer thing.