How do you change a air conditioning belt on a 1997 QX4? Thanks?

Drop the motor splash shield. The tension pulleys on all the belts have a center nut you need to loosen and then an adjustment bolt under the pulley that you need to loosen so you can remove the belts. Install the new belts and tighten them with the adjustment bolt until you can barely twist the belt 90 degrees by hand. Tighten the center lock nut and install the splash shield. Hand spin each pulley when the belts are off to see if they are dry or make noise. Replace them if bad.