Yes they do need to be packed, and you might want to change the seal while your in there. The seal costs about 79Cents.
They need to be checked, cleaned and repacked.
The front wheel bearings are a sealed unit so repacking is not possible nor necessary.
You can't ,they are a sealed unit.You have to buy a hub assembly.
http://rkrenn.com/xterra/howto/bearing/bearing.htm This link get you past the pads, rotors all the way down to the bearings.
Wheel bearings on 1995 Geo Prizms are sealed units and cannot be repacked with grease. You must buy new bearings to be pressed on hubs by mechanic with proper tools. If bearings are worn, replace ASAP before bearings start damaging hubs, you'll save bunches of money.
To change front rotors on a xterra u have to remove the brake caliper and brake guard off the rotor and then remove the gold cap off the hub and unscrew the two screws holding the wheel bearing in then unscew the holding plate that holds the bearing remember which way the holding plate goes when taking off... then remove the hub and the rotor comes with it ... then the screws going around the hub on the out side remove theses and the rotor comes off .. but i also suggest repacking the wheel bearings and replacing brake pads pads with the new rotors ...
The front automatic hub from your 2001 Xterra will fit on your 2000 model Xterra. The front automatic of's are exactly the same.
The 2013 Nissan Xterra has 58.3 in. of front shoulder room.
The 2006 Nissan Xterra has 42.4 in. of front leg room.
The 2011 Nissan Xterra has 58.3 in. of front shoulder room.
The 2009 Nissan Xterra has 58.3 in. of front shoulder room.
The 2003 Nissan Xterra has 54.5 in. of front shoulder room.