a press. the hub is pressed into the knuckle. Once you press the hub off the knuckle you can then knockout the stud & replace. Chances are that you will damage the wheel bearing in the process of pressing it apart. The bearing runs msrp $58.85 or $44.14 at OEM Acura Parts
I have a 94 & had a bad stud on one side I just went to a junk yard & got the whole knuckle assembaly for 50. I got the whole knuckle caliper rotor & etc..