Do I tempt fate and try to replace other stud? I have new studs. I cut remainder of stud off the back, ground it flush with dremel. Mixed a bit of ATF & DOT3 applied and came out fairly easily.

 I have applied the mixture to both sides of other stud. I’m going to the hardware store to get some nuts to stack on the stud and see if that’ll get it out.If it breaks closer to the manifold I may be fucked.