We use the Snap-on collet style stud remover.
With an oxy-acetylene torch coupled with a 3/8 (locking the collet) and 1/2 impact gun (removing the stud), you can do the job in about 20 minutes without damaging the stud.
This becomes important if your reusing a high quality stud like the Supertec head stud.
The collets are available in almost any thread pitch.
