You don't. The tension on the belt is held tight by a spring loaded tensioner idler.
The power steering unit and the alternator are both driven by the serpentine belt. Loosen the tensioner pulley and the serpentine belt will become loose. Put the new serpentine belt on and tighten the tensioner pulley.
Buy a Chevy!!!! That was a big help. Most but not all serpentine belt systems have a spring loaded tension pulley that just holds constant tension on the belt. If there is a tension pulley, it will be the one pulley that is not attached to anything like the alternator or AC. After that, the alternator is the most likely to be the one that adjusts.
Serpentine belt? You may have to remove to tighten alternator
Put the serpentine belt around the pulleys on your 2001 Chrysler LHS. Tighten the serpentine belt by pushing the tensioner pulley to the left. Tighten down the tensioner pulley and the serpentine belt will be tight.
You can tighten the serpentine belt on your 2005 Chrysler 300 by tightening the tensioner pulley. Push the tensioner pulley to the right until the serpentine belt is tight.
Loosen the tensioner pulley. The serpentine belt will become loose and can be removed. Put the new serpentine belt on and tighten the tensioner pulley.
You can change the serpentine belt by loosening the tensioner pulley. When the tensioner pulley is loose and the serpentine belt will become loose. Put the new serpentine belt on and tighten the tensioner pulley.
Loosen the tensioner pulley on your 1988 Chevrolet Corsica. When the tensioner pulley is loose the serpentine belt will easily come off. Put the new serpentine belt on and tighten the tensioner pulley.
You will need to loosen the alternator belt with the tensioner pulley. When the tensioner pulley is loose the alternator belt will become loose. Put the new alternator belt on and tighten the tensioner pulley.
All you do is look for the tension pulley and tighten it, see below
If it is a serpentine belt you replace the tensioner pulley
You will need to loosen the tensioner pulley. Slide the tensioner pulley to the right and the serpentine belt will become loose. Remove the old serpentine belt and put the new serpentine belt on. Slide the tensioner pulley to the left and tighten it.