Curious,I don't see how this help the op remove the lower ball joint. Great right up for removing wheel bearing though.
I had to go out and look to see how the lower ball joint is attached to remember how to remove it.
Here is what I would do;
Jack the truck up and get the front wheels off the ground.
Place jack stands under frame.
Loosen bolts at frame and lower control arm don't remove them just loosen a couple turns to remove preload on the rubber bushing.
Remove cotter key on lower ball joint castle nut and loosen castle nut but don't remove completely.
Looking at the spindle there is a large piece of the spindle on the inside of the ball joint mount.
Using a impact hammer or "BFH" hit that several times or untill the ball joint pops loose (the ball joint is a tapered fit by hitting it you will get the taper to distort a little with the vibration of hitting it and it will pop loose.
Remove tension on the torsion spring and remove.
Remove the castle nut from ball joint and slip the lower arm away from the spindle.
If you want to remove the two frame to a-arm bolts and work on the arm out of the truck you can do this now or replace the ball joint on the truck either way works.
Installation is the reverse. Don't tighten A-arm to frame bolts until the wheels are on the ground as this prevents pre-loading the rubber bushing and they will last longer.