For the fun of it I checked Rockauto and saw that the 05 only listed the lower ball joint. The 06 however listed both upper and lower. I did not know the the engine size but I believe the 06 does have upper replaceable ball joints.

 

In the 06 both upper and lower are replaceable. Do not use cheap ball joints. It is not a job you'll want to do more than once. A factory service manual or even a Haynes manual will have the procedure. You may also want to replace the struts since you have to remove them to do the job.

Good luck.

 

They are replaceable but you don't need to remove strut by any means. Remove wheel, take nut off the upper and give the yoke a good smack with a solid hammer, right on the side of where the joint is. This should allow the tapered stud to slip from the yoke. You may want to thread on the nut again a bit to avoid damaging threads. Now remove the snap ring and press the BJ out, usually downward. Just use common sense to assemble the press kit using suitable parts. If its really stuck get out the torch, but that's rare with a good impact gun. This procedure is the same for all trucks. You might want to disconnect ABS or brake line is some cases to avoid stretching, once again use common sense for this. Good Luck Bud.