Okay..
on the V6... you follow the routing as you say you know..
Loosen the tensioner with a 3/8 breaker bar in the square hole on the front of the tensioner.
remove the belt.
replace the belt around all pulleys with the RIBBED SIDE touching all grooved wheels. The only thing you don't wrap the belt around is the lowest, point (alternator at the rear, or AC at the front, I prefer AC)
Replace it on all but the A/C (INCLUDING placing it on the tensioner), then using your breaker bar you remove tension on the tensioner, HOLD IT THAT WAY and slide the belt (now that you just made some extra slack) around the A/C