X2.There is a detailed write-up on a solid front axle rebuild in the FAQ. It helps to have the factory service manual.
I would rebuild both sides if I was going to tear into the axle. You can order the necessary parts from CDan or one of several vendors. I bought my rebuild kit last year from Marlin Crawler and also bought their heavy duty seals. They produce a high quality kit with bearings and everything equivalent to OEM.