93 buick lesabre serpentine belt

[fsspear]

exactly how do i relieve the tension on the serpentine belt to replace the alternator?

[tman]

There is a tensioner pulley diagonally between the water pump, and power steering pulleys. Use a breaker bar, or a long handled ratchet to loosen the tension. It's I think a number 18mm socket. When putting the belt back on, be sure to get it in all the little grooves.