Releasing Tension on Idler Pulley
 

I am trying to change my aternator and can't seem to figure out how to release tension on belt idler pulley. i have the bolt loosened but don't quite know how to release tension. I'm reasonably sure it is not too complicated but don't want to break anything prying too hard.

Appreciate any help.

what year and engine ,s-10 or blazer ? usually there is a a Square hole in the idler pulley bracket to put the 1/2 hex of a breaker bar in to pull back enough to releaase tension on the spring in the idler and remove the belt .

Yeah, there is either a square plug for a breaker bar/ratchet or a bolt through the pulley that you can just pull it out of the way with a wrench to take the belt off. It is spring tensioned, so you can't take the tension off, but rather lessen the tension and remove the belt.