You have the ball joints unloaded from spring tension with the torsion bars relaxed and disconnected. Now just support the control arms against gravity when you start chiseling the rivets.
Longbox described suspension loading quite well, the only difference in your case is your torsion bar suspension, rather than coil springs. Doing the wrong thing with either of those suspensions can cause a lot of damage, including to you, so this is not to be handled casually and without a full understanding of what you are doing. Suspension work is serious business and intolerant of mistakes. Bear with me if I sound like I'm harping on the topic.
Ok, after the harping, when you have finished the ball joint installation, wind up the torsion bars before you lower the vehicle. Otherwise you will be lifting the weight of the truck as you tighten the torsion bars-- if you haven't already thought of that point.
Harvester
