Its very easy to change, just make sure you put a drain pain/plastic on the ground before doing so, wear some eye protection in case the filter slips and the gas starts a pouring on your face(yes it happened to me).
Basically you pull the fuel pump fuse out of the truck(located in the driver side fuse box inside the truck). Start the truck until it stalls, start it again to make sure it stalls fully so no gas is in the system(less fuel spillage).
The fuel filter is located near the mid/rear section of the passenger side. Its before the rear wheel behind a metal cover plate thats facing towards the front fo the truck. You will see two gas lines one on each side of it running behind the cover plate. Just unscrew the cover plate, loosen the two tubs on both sides of the filter and pull the right side out first from what im told, use a golf tee to plug it up and then work off the other side and do the same thing. Take note of how the filter is set up because u need to put in that same way. Remove the bracket off the old filter and mount it onto the new one. Put it all together, if you have trouble sliding the tubes back onto the filter just use some gas/vasoline(not much) to help lube the tube onto it. Put it together, put the fuse back in, start it up and check for leaks.
It took me 15 minutes and I've never changed a filter before, I just looked at a picture and read about it on this forum.
Look for this under the area I said, unbolt that and you should be able to see it. Can thank Dezurtrat for that pic, he took a really nice snapshot of it.
2004 Nissan Xterra XE V6
+Front/Rear Bilstein Shocks
+Bilstein Steering Stabilizer
+Kumho Road Venture APT 265/70R16
+Intake Modification + OE/Filter