I would like to get some help on replacing a pulley from serpentine belt it's makes a loud whinging noise I've changed the alternator replace it with a new one and still making that same noise can hear it coming from one of them but want to make sure I do it right

 

well which pulley are we talking about?

 

It's the tensioner pulley

 

the pulley itself remove the belt loosen the bolt to teh pulley take it off install new one install belt.