Can anyone tell me when changing front rotors on my 2002 xterra do i need to remove the bearings.

thanks

Yes, you have to remove the wheel hub, which requires removing the outer bearing. The rotor is bolted to the wheel hub. Here's 90% of the procedure (not including separating the rotor from the wheel hub) plus a little extra regarding the actual bearing re-pack:
http://rkrenn.com/xterra/howto/bearing/bearing.htm

Brent