I have a broken hammer stud, I have located the part online but have no idea of how to get the old one out. I have tapped on frame from the back side, heated it, and done both together. It is a model 19-4.

STOP Take it to a gunsmith that knows how to do this. You can really screw up your 19. Good luck.

Most gunsmiths will not attack this problem! Send it to a shop that knows what it is doing, like Cylinder & Slide in Fremont NE.

Just so you know the original hammer stud is induction brazed into the frame, which is nearly as strong as welding. You will destroy the frame by trying to drive the stud out!