Here are the diagrams for the serpentine belt. I do not have the data of the bolt size and it should be either 14mm.
REMOVE V-BANK COVER SUB-ASSEMBLY
REMOVE NO. 1 ENGINE UNDER COVER
REMOVE FAN AND GENERATOR V BELT.
While turning the belt tensioner counterclockwise, align the service hole for the belt tensioner and the belt tensioner fixing position, and then insert a bar of Ã 5 mm (0.197 in.) into the service hole to fix the belt tensioner in place.
HINT: The pulley bolt for the belt tensioner has a left-hand thread.