I have done pads and rotors on vehicles before but never had to remove the bearings to get at the rotor. The Pathfinder requires you to take off the wheel, pop the bearing cap and then completely remove the bearings, which once you have done it, isn't that hard.
**The tricky part is that you need a specific tool to properly torque and seat the bearings to factory specs. This is the tricky part as I couldn't find one at Canadian Tire or Lordco. Nissan wanted $100 for the tool which kind of looks like an "h" where the top part has a nut for torque and the two other ends insert into two small holes around the bearings. I ended up making my own (which took the longest of all because it kept on breaking).
In total I suppose I spent about $275 (high end rotors and pads) from Lordco (w 30% discount). Budget and Midas wanted $575 for the job which at the end of the day isn't so crazy.
The first wheel took my buddy and I (including tool manufacturing) about 4-5hrs to complete (very long). The second wheel took us only about 30 minutes !!!
Anyhow, depends on how handy you are, your tool collection and ability to get a good price on parts ! Check out the "Service Manual" located under R50... it gives you a step by step process, with photos. This is very helpful when re-assembling the hub as certain washers, o-rings and retainers have to go back in the same order !
Good luck !