Can someone tell me where I can purchase a service manual for a 2004 Xterra? I need to change the brake pads, maybe rotors on my car. thanks.

Try the "backyard mechanic" section, I know we've answered that there a few times...

Pad swap:
http://mywebpages.comcast.net/xterra/tech/FrontBrakeJob.txt
Rotor swap is 6 bolts more than this (to separate the rotor from the wheel hub):
http://www.rkrenn.com/xterra/howto/bearing/bearing.htm

Manual:
The Haynes/Chiltons manuals will cover this basic stuff even though they are only officially good to the 2000 or 2001 model year.
Or you can download the official factory service manual by purchasing a $20 one-day subscription to Nissan's site www.nissan-techinfo.com and you can view and save it in PDF format.

Welcome to XOC,
Brent

ebay

Uh, no. You're giving your money to a theif if you buy one of those CDs on Ebay.