Um, my Miata has 100K miles, what if I find a low miles new hub at a junk yard?
Getting the old stud out of the hub only takes a few good whack with the hammer. The stud is not as tight in the hub as a wheel bearing race or anything like that. Popping the stud out with a hammer may not be the best way to do it, but it works and has worked for I would guess hundreds of thousands of studs over the years. I'd also be REALLY surprised if most shops went through all of the trouble of pulling the hub and using a press, essentailly turning a 5-10 minute job with a couple of hour job.