How do you release tension on a/c belt on 2004 GMC Yukon XL 1500

I want to replace a/c drive belt on my Yukon, how do I release tension on the belt and then how do I adjust the
new belt after I replace?

Asked by for the 2004 GMC Yukon XL 1500
You can find very good repair manuals with step-by-step instructions here:

Thanks, but I don't want a manual just want to talk to someone who has done it before.
1 more answer
The a/c belt is located behind the long main drive belt. you can get a socket and ratchet on the idler pulley bolt lift it up slack will get in the belt