you could really save yourself some serious cash and do it yourself. it's one of the easiest things you can do. all you need is a jack, jackstands, and a few hand tools.
While that is true, if he's not even sure how many there are then working on his truck just may not be his thing...
Oh - be aware that the front and rears are not typically the same part number - at least that's true on the '00-'04 Xterras. The front shocks are much smaller/shorter and they mount differently.
Enjoy the Xterra
