Do you have to code the TCU (EGS) to the car with NCS or something on the E53 before it will recognize?

Pulling front axles can be a real PITA, but since you are out of the rust belt, maybe you will get lucky. the splines in the hub are tapered (I think) and regardless its a real tight fit getting them out and back in? I made special tooling for both removal and installing.

People rebuild axles, buy Cardone or other rebuilds from rockauto, etc. I have bought my last two X5 driveshafts from CVJ Axles in Denver...and have been happy with them