How do you replace the serpentine belt on a 2000 Chevy Tracker 4x4 2.0L engine and AC?

Use a wrench to relieve the preasure off of the belt then remove the belt and replace it using the schematic on the fan shroud. If it doesn't have one draw one before taking the belt off. Don't rely on memory.

Looking at the front of the engine there are two idler pulleys; using a 14mm wrench/socket turn the idler pulley closest to the alternator/power steering pump from 12 o'clock to 3 o'clock this will release the tension on the belt.