Not good! The axel must be removed from the upright to gain access to the stud. Usually the upright must be removed from the car, the axel nut removed (should have been torqued to 300ft lbs), yoke removed and the axel pressed out with a hydraulic press. The brake rotor must be carefully supported a full 360 degrees to prevent it from breaking during the axel pressing. Broken studs are one of the reasons I never let anyone mess with the wheel studs, epically tire stores. This page might be helpful
http://www.panteraplace.com/page87.htm