Panda, removing the lower ball joints takes about 2 minutes once you get the spindle assembly out of the way. How I do it is to use a 3 pound hammer and after you remove the retaining clip, you have a jack under the lower A-arm and you beat the ball joint out. I find using a fairly large socket helps as you can knock the ball joint all the way out. I have a socket that I have sacrificed for this very job. Then putting the new one in requires the use of the ball joint press. But, by that point, installing the new ball joint is cake.
LIke was mentioned, the uppers are easy. One big thing though is to match mark your bolts that hold the upper A-arms to the frame. You want the line to run from the washers to the brackets welded on the frame (or simply mark the washers so the line runs to the 12 o'clock position). Why do I say this? easy, if you keep the bolts in the same spots, as long as you put the bolts back how you found them, your alignment should be pretty close and you don't have to run out immediately to get it done.
If you need more tricks, let me know. Like I mentioned, place a jack under the lower A-arm to hold it in place. If you don't, when you break the ball joints loose, the torsion bar is going to attempt to wrap the A-arm under the truck. So, put the truck up on jackstands, then place the jack under the lower A-arm to provide just a small amount of upward amount of pressure.