The upper ball joints can be changed with the control arm on the car, if ya want. You will have to drill the rivets out, tho...the new ball joints should come with bolts/nuts to reinstall.
Jack the car up and put jackstands under the lower control arms, as far out as ya can get them with the tire/wheels still on...just make sure they are sturdy.
Remove the cotter pin in the ball joint, take the nut loose, but not all the way off. You can either use a "pickle fork" to separate the joint, or a hammer....or you can possibly borrow/rent the special tool for it.
Drill out the rivets, and replace in reverse order.

Adams advice is very good except for the hammer. Don't go wailing on anything with a hammer. The A-arms are aluminum. Very easy to bend. Use a pickle fork and grease the flat sides of the picks. Hardened steel and aluminum gall terrible. Or, loan the ball joint popper from Autozone or such.  I've redone several front ends on C4's. Ball joints, bushings, etc. The hardest thing to replace is the bushings in the upper A-arms. If you’re a real nice guy you could put a light schmear of anit-seeze on the ball joint tapers for the next guy.

Good luck.

 

When putting a new spring in last year I had to deal with getting the lower ball joint tapers free of the yoke. Since aluminum grows quicker than steel when warmed up all I had to do is use a propane torch to heat the aluminum around the taper. It doesn't take much warming at all.

You should be aware that the stock spring curls a lot farther than you might think. That's why the manual indicates a special tool is required to deal with it. I changed the rivets on the upper for ss bolts and nylock nuts. Manual says just knock them out once the heads are removed. I can tell you that was an understatement on mine and I had the entire arm on the bench for polishing at the time. A little heat might help as would some some good penetrating oil since the rivets do corrode a little because of the dielectric between the steel rivets and aluminum control arms.

|UPDATED|5/9/2013 6:16:17 PM (AZT)|/UPDATED|

I learned the hard way that grinding off just the rivet heads doesn't always get the job done. When the factory heads the rivet the shank sometimes bulges out and locks itself into the aluminum. I've found two methods to handle that. Either you do a very good job drilling the whole rivet out on center or if your worried about keeping the drill true, I've used an air chisel with a a round tip to drive the shank out after the heads are ground off. As stated, be super careful around the mono spring since they're loaded pretty heavy. Especially the original Z51 springs.

Hey Joel, how or what do I have to do to deal with the composit spring? I have dealt with coil springs lots of times and know to use coil spring compressors. How bout on the C4? I don't want to screw something up, which I have in the past, or loose half my jaw because the spring is under tension?

  what do I need to do to keep from hurting me or more important, my Corvette as far as the composite spring. It must be under some kind of pressure.

  Can you explain in more detail what you mean about using a floor jack to unload the spring? And did you have the car on jack stands at the time. And where did you place the floor jacks? As you can see I am a wealth of questions, but not answers.

If you are only doing the UPPER ball joints, place your jack stands under the lower control arms, as close to the lower ball joint as you can SAFELY put them. You won't need to worry about the spring when only doing the upper ball joints. With the weight of the car on the lower control arms, there will be no spring pressure on the upper control arms. Leaving the shocks connected will also give you some added insurance.
Now...if your also doing the lower ball joints, it's a whole different scenario....you will need to place a jack under the lower control arms to keep things from getting hurtful....as others have stated.

|UPDATED|6/5/2013 10:13:14 AM (AZT)|/UPDATED|