ok, so is the problem just with the grease nipple? because you can thread those out and replace them seperatly.
As far as replacing one ball joint, once you have the spindle off to replace on, it's not much work to do the second one. As far as parts cost, ball joints are fairly cheap.
It wouldn't be a bad idea to check the alignment after doing this job, but ifyou mark the eccentric before you take it apart, and put it back in exactly where it was, you should be pretty close.