If you haven't done this i would seriously recommend giving it to a diff expert. In my opinion it is harder then doing clearances on an engine. The shims will never be right once you change bearings, and shims are special order from Nissan. Once you do a heap you get a feel for where you need to go to get correct bearing pre load and correct mating between crown and pinion but takes multiple disassembles of the diff to get it right, even for a pro.
If you want to do it, you need a good bearing puller, press, bearing blue, torque wrench and a few punches and hammers. Also a bearing pre load gauge.