oh I didnt realize the nut and wheel were still on the car. Id just get a breaker bar or a t handle lug wrench, If you apply max torque back and fourth a few times the stud will fatigue and break. Gotta man up a bit on the wrench but they arnt as tough as you might think.
Then hammer out and replace as described earlier. In the internet age I imagine sorceing a new stud for a miata is not a difficult afair
