So I'm trying to get the head studs out of an extra cylinder I have and can't get any of them unscrewed. The ones on my other cylinder have a square on top for a wrench to fit on. These do not. I tried vice grips and also tried putting two nuts on it and using one as a jam nut and trying to do it like that. That didn't work either. How do I get these out?
That's what they look like
That's what they look like