[Rick Parker]

As Bonos mentioned above, replacement of the gear carrier is relatively easy to accomplish. As far a replacement of the ring and pinion, it requires experience to know the right "Feel" for the assembled pinion after replacement with new bearings. You must also have as mentioned some specialized heavy duty tooling, including hydraulic press, adjustable bearing clam shells to remove and replace the bearings, a vast assortment of different shims, a large capacity torque wrench that approaches 200 + lbs, and a very stout LARGE VISE to hold the companion flange while the retaining nut is being torqued. Most of these are not in our home shops. This is a job best left to a professional shop that does this often. Considering your location in the Heartland of Nascar, you should have no problem finding a shop capable of doing this. With access to the correct tools and some written an illustrated information this is not an overly difficult job. However it is not one you want to take chances with. The learning curve is steep, even if you have access to the tools. If the gear meshing pattern is incorrect or the bearing preload too loose or too tight you will be buying a 3rd set of gears. Repeat: "Best left to a pro."
I would also suggest using a machined bearing spacer instead of the collapsable one that is more commonly supplied because it will maintain the pinion bearing preload much better, especially with an engine such as yours that develops a lot of torque.