Remove the belt. Remove the bolt in the center of the spring. Remove the tensioner. Reverse to replace.
Rick
I'm a retired ASE Master/L-1 Technician. I still keep current with the latest automotive technology. Visit my blog for cool articles and TSB's: http://free-auto-repair-advice.blogspot.com
you have to loose the belt in order to slide it out by releasing tension on the tensioner pulley ,what you do it`s sore of a tight motion clockwise on the tensioner bolt it`ll loosen the belt and then you can slide it out, to install it do the same.
Tensioner pulley below the alternator. Should be a 14 or 15mm socket and turn counter-clockwise.
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.
Accessory drive belt and or belt tensioner.
A 2000 Chevy S10 does not have a timing belt.
T55
Chain
Find the idler tensioner pulley and retract it. You then will be able to easily remove and replace the belt.
Chain.
get a wrench that fits the tensioner and pull it back until the belt has enough slack to go on the alternator
If it's like my 93 S10 Blazer, then you use a wrench or 3/8 ratchet fitting to release the tensioner.
timing CHAIN