Seperating this lower ball joints stud from the hole in lower arm is a challenge. We can hardly get at that cotter pin or get a tool on that nut, especially in the hanging down position. Would be easier to unbolt the lower ball joint from the spindle. Or separate upper arm at ball joint or bushings so the spindle assembly tilts outward to access lower ball joint stud hardware.
I found I could unload the torsion bars, pull eccentric bolts at upper bushings, defeat ball joint hardware, leave nuts on a few turns, reattach upper arm to chassis and reload torsion bar. Torsion bar load serves as helper in separating ball joints from arms. My procedure might not help you with a broken adjuster though. Good luck with it.
