Torsion Rod Adjuster Stuck

When you get the spindle assembly out where is workable, zip that upper ball joint nut tight again with a impact enough that the tapered stud sticks in the bore. A drop of lube on the threads if needed and zip the nut all the way off. Splitter will pop the stud a lot easier this time.
Now... splitter worked on upper ball joint because that arm affixed in 2 places. The lower arm has a lot more lateral movement, even more without the stud rod attached. Much of your effort with splitter and hammer is lost in the movement of that arm. If you have to unbolt the lower ball joint from the spindle, put the lower arm in a vise to separate the ball joint from it... we do what we must to geter done.