I want to do it myself. the upper ball joints were a breeze. how bad are the lower ones to do yourself?

Not too bad. The difference is you have to pull the hub assembly to do the lowers on a 4x4. You will need a 1-3/8" (I believe) socket and a 1/2" or 5/8" drive torgue wrench. There is a guy that posted a great write up on line. You can probably find it by Googling F150 ball joint repair. If not go to the Ford F150 forum and check the Maint. section. Did you get the alignment checked after doing the uppers? Also, you might need to tap the upper with a hammer when you pull the hub. Loosen the nut and leave it on to protect the threads when you do.