I just experienced a stripped wheel stud and this thread came up in a Google search. So I decided to update it. I always hand torque my lug nuts after cleaning the threads so was surprised this happened to me.
I was able to get the lug nut off after:
soaking it in penetrating oil
removing the other three lug nuts
having a helper twist the wheel to put pressure on the stud
using an impact
Once the nut was off there were no threads on it or the stud. I used a 3-pound hammer to knock the stud out the back.
I located a replacement at Advance Auto after the counter man allowed me to poke around the inventory in back. This works:
M12-1.25 Serrated Wheel Stud - 14.35mm Knurl, 42mm Length
www.dormanproducts.com
It was a little longer but no biggie. I grabbed another lug nut there. It was for tapered wheels and I flipped it over so the flat spot was down on the washer. I put all four washers on the new stud and used the impact to pull it through. My first time doing a wheel stud.