It is pretty straightforward if you are mechanically inclined. Also, don't forget to get an alignment once you're done installing the new rack. On my vehicle, I replaced the ring and pinion, and it was an easy job since I have a repair manual.
Nice choice on wheels. How much it cost you? And how's the quality and finish? I found the same replica jeep str8 wheels at http://4wheelonline.com and I'm thinking of buying a set for my DJ.