There are two styles of ball joints, press in and thread in. You need to make sure you get the right type. Rare Parts in stockton CA makes good stuff with a stock and sometimes an upgraded part called their Diamond Series-if you can buy at jobber rate good prices, Fusick olds has them I think, Kanter Bro but probably pricey, there are others as well, or try for the NOS somewhere.
Your shop manual has full procedure for replacement. Keep pressure on ball joint to prevent it from turning when working nut.
I’d do a thorough check of all of them if you have a bad one, especially lowers.