ok about 6 months ago i ran into this problem...out of the 4 studs i got 2 out the other too i let the machine shop do...believe me it was worth it i spent 12 hours trying to get the 2 out...i sprayed them with about 2 cans of blaster...i also heated them...and i used the tighen loosen method for several hours on both...so try it and see how it works for you...even if you only get 1 or 2 out that reduces the bill at the machine shop...but if you stick to it you will get them all out ...i just dont have the patience