How do you replace a lower ball joint on a 99 Pathfinder 4wd?

First you need to jack the vehicle up and support it on stands, then remove the tire. Remove the torsion bar and disconnect the lower shock mount, and remove the stabilizer bar connecting rod from the lower link. Loosen the lower ball joint nut, and use a ball joint separator to separate the ball joint from the lower link, then disconnect the tension rod from the lower link. Remove the front lower link pivot nut and push the stud out, then remove the torque arm from the frame. Remove the ball joint by removing the retaining bolts and install the new one, I suggest you replace the bushing as well.