We just did one last week. After having tried rebuilt units and even new ones from various suppliers we decided rebuilding it was the way to go as we haven't had great luck with either of these approaches.
The kits come with the "O" rings, etc. that you will need. There were no special tools needed. You can even get the kits from NAPA stores. It's pretty straight-forward but putting some P/S fluid on the rings will help reassembly and you will also have to balance the unit. That's done by adjusting the nut on the end of the unit which is under the pressed in cap. Be sure not to overfill the P/S unit on the initial fill. We manually turned the steering back and forth to eliminate some of the air in the lines before starting it. Just check the level after starting the car and moving the wheel back and forth a few times and add whatever is needed.
I was warned, when starting the car, not to place your arm through the steering wheel to reach the ignition switch as the wheel can move suddenly and trap your arm. The balance adjustment usually takes only small movement in the adjusting nut and it's finished when there is no pull to the right or left.
Hope that helps. I'm sure others will add their own thoughts and experiences.
Rich Lagasse
