I did one on my Wife's 2011 Nissan Quest with the same engine as the Pathfinder.
Original one lasted around 130k miles, so can't really complain.
The one on the Quest wasn't great, but I think I got it done in about 4-5 hours.
Had to pull the lower bumper splash shield, and the passenger fender liner.
Then I unbolted the ac compressor and let it drop down (was able to leave all the refrigerant hoses connected so that was a plus).
The upper bolt was a pain to get to, probably the worst part of the job!
With it unbolted there was just barely room to get it out through the wheel well. If you had it positioned just right it would slip through the opening between the subframe and the frame rail.