[Mrmerlin]

you would not rebuild a lower ball joint it would get replaced,
you need a magnet to see if the housing is steel or not, if its not then you need new lower BJs. .

Also on the lower BJs, you could remove one of the eccentric nuts at a time and clean out the respective well it sits in , a small dab of antiseize or grease on the rotating part and bolt shank will make adjustment easier and prevent the eccentric from being stripped out when the car is at the alignment shop