Is this a V8?
If it is, you take tension off the 1st belt by loosening the air injection pump on its mount. Remove belt.
Take tension off the A/C belt by loosening the capscrew on the tensioner. It looks like a pulley on an arm; which it is.
Take tension off the alternator belt by loosening the alternator on its bracket and using the star gear to clock the alternator to the right. Remove belt.
Take tension off the power-steering pump/ waterpump belts (2) by turning the capscrew on the powersteering pump. Loosen the pump mounting bolts before doing this. Turning the capscrew, which is near-vertically oriented, adjusts tension via a plastic nut that is held rigid to the pump bracket.
Remove both belts.
Installation is reverse, starting with the inner most belts and working to the front. Tension each belt by taking a straight-edge and putting it against the pulleys of the longest span the belt makes. Tension until you can just deflect the belt about 1/2" from the straight plane defined by the straight edge.
Tighten more if a specific belt is squealing upon idle.