I've never seen a wheel stud that could be easily removed. Even if you could gain access, you need to press/drive the remains of the stud out and this is best done with the hub off the car.
Those studs are hard to break; what happened?
The threads should be clean, but not lubricated and tensioned to about 80 ft.lb. in stages. Particularly with alloy wheels, the tension point comes up rather suddenly. I've had studs over-tightened by tyre-fitters (to about 200 ft.lb.), so I know that the threads are quite strong. The threads, BTW, are usually rolled into the stud rather than being cut, in the interests of strength.
If you lubricate the threads and you have steel wheels, you can easily crush the wheel centre if you are too enthusiastic with the wrench; the threads need to have a bit of "bite" to them for correct tension.
It's worth buying or borrowing a torque wrench to make sure the tension is correct. I've only recently bought a torque wrench, but I've found that my usual routine for tensioning had been giving me very close to 80 ft.lb. anyway. -Years of practice!