[Superman]

Once the loctite is melted, head studs come out fairly easily. Without the loctite being melted, I suspect there is a substantial risk of snapping a stud or worse. And I would guess that this risk would greatly increase with use of an impact wrench. In other words, if you don't melt the loctite, I think you're likely to make a mess. More likely if you use an impact wrench. If you do melt the loctite (you will need a HOT flame for this....much hotter than propane), then you can use just about anything. I used a small pair of vise-grips. They came out easily.