Chevrolet Repair: Chevrolet K1500 gage cluster failure, gm dealer, chevrolet k1500

Question
Why does the cluster replacement have to be done by a GM dealer and what exact reprograming is needed? I am curious why I can't obtain the cluster and replace it myself. My 2003 Silverado K1500 has 104,000 miles and $500 to get the speedo functional again is not my idea of a fair shake from GM.

Answer
It needs to be done by the dealer because the cluster needs to be programmed two different ways.  The first is with the techline computer to download the actual data for the cluster.  The second is to set the cluster up with the tech 2 to input correct mileage and learn the cluster to the car.  The job is fairly involved and the price quoted is correct.