I am taking liberty to start a thread in the FAQ section on this, since information using the search function was limited when I had to do my research on this.
If you plan to replace the factory ball joints on your Pinto, it is probably a lot more work than you might anticipate, especially if you are a semi-novice at home mechanic like myself. I was not expecting it to take so long, nor for it to require so much effort.
First off, the factory ball joints are not bolted into place like the replacements will be. From the factory, Ford riveted them into place using 3/8" diameter steel rivets with flat heads. Ford's recommendation to ball joints service, is not to service them! That is, they recommended an stressed that the ENTIRE CONTROL ARM be replaced, and after doing the work myself, I can see why. Haynes, Clymer, and Chiltons manuals will all tell you the same thing, to replace the control arm.
If you decide to go through with doing your own ball joint replacement, I would recommend replacing the control arm bushings as well as the strut lower control arm bushings as well. Since you will be under there anyway, taking it all apart, you might as well save yourself the cost of another undue alignment in the future by getting it all done at once. Just be sure to note where the control arm sits before you remove it by scribing the arm around the bolts, or even painting the bolt area before removing it, then aligning everything during reassembly. Either way, you will need an alignment in the end.
I don't have much to really point out, aside from a tip on removing the original steel rivets an easy way. Doing it this way saved me 30-45 minutes of hammering with a cold chisel.
Start by cutting an "X", or a cross, straight down into the rivet head (pictured), this degrades the structural integrity of the rivet head and makes chiseling the remainder of it off VERY easy. It took me about 15 minutes to cut off the heads of the upper control arm rivets with this method, while cutting straight through the solid head took me about an hour - hour and 15 minutes to do without this step. I used a dremel with a reinforced cutting wheel to cut the heads, and then finished up with a small cold chisel (pictured), sharpening it after cutting off the head of each bolt. I sharpen my chisels using my dad's bench grinder (pictured).
Once the head is cut off of all the rivets on one side of the ball joint, it doesn't matter which one, you can then take a drift to the center of the rivet, support the arm in a bench vice or something similar, and pound them out. Once done, the joint should split into two, with the ball joint on the top of the control arm, and the boot+retaining ring on the bottom.
The final steps would be to clean up the control arm, then install the new ball-joint, but this time using nuts and bolts. in the end, the nuts and bolts will save you a TON of work later if, if you should need to replace them at a later date.
I hope these helps someone in the future. If anyone else has something to post about ball joint repair, please post it! It would be nice to have as much info as possible, centralized and available to everyone.