if it has a serpentine(one belt for all the accessories)belt it is loosened at the idler pulley. the idler pulley will be the one that isn't driving an accessory. it will probably have a square hole in the center of it for a 3/8" or 1/2" inch drive (a ratchet or breaker bar will pop int it as if the pulley were a socket) and it may also have a nut or bolt locking it in position,which will need to be loosened or removed. with the ratchet (and you may want to use a breaker bar as they can be strongly sprung) in the pulley apply force in the proper direction to pull the idler pulley away from the serpentine belt it is spring loaded against.when it is loose the belt will slide off of all the pulleys easily. just pull it off any accessory and you can let go of th pulley. if the locking bolt or nut is still in th pulley assembly and can be tightened with the pulley in the position where you pulled the belt off you can tighten it while you have the pulley held back and it will be easier to reinstall the belt. VERY IKMPORTANT... if the car no longer has the sticker on the radiator shroud or airbox or the underside of the hood that shows the correct routing of the serpentine belt, get a pen and paper and carefully and fully record the correct route the belt follows. it is a real drag to have to figure it out without that diagram(believe me, i wish i didn't know how much of a drag) so look for the sticker. in 15 years(your cars age) it may have been removed or rendered illegible. oh and if it isn't serpentine(though i'm pretty sure it is) the belt will be around one or two pulleys. if one (the alternator) find the lock bolt(it's usually in the tensioner adjuster rack) remove it loosen the other bolts (the ones the alt can pivot on) and the tension adjuster bolt just gets turned counterclockwise until the belt is loose enough to be removed. install the new belt, turn the tension adjuster clockwise until well tensioned, tighten the pivot bolts and the lockbolt, and you are ready to go. hope that is enough to get the job done. good luck.
