The problem is the stud is usually rusted in from behind. Get some WD40 on it for a while. The thread is M12x1.25 fine pitch, so get two bolts and tighten up on each other and unscrew the stud. Nissan bolts are the correct thread/pitch. You will need shallow open ended bolts in order to get two on the stud and you may need to take the disc off to get more length on it..
