Nismo 4.6 Gear Install

[240sxOwner]

I posted about trying to find these gears about a week ago, and after some help i managed to get a hold of Nissan Motorsports and get the 4.6 Ring and Pinion gears. I just wanted to know how hard the install would be: If someone of basic knowledge could do it: or a good price to have a shop do it for me. Ive heard that the only hard part is shiming the gears just right. Im looking to save some money...but i want it done right. Sorry for the long post....Thanks for the help