#1 shows the tensioner pulley. You have to rotate it clockwise to release tension on the belt. Then route the new belt according to the diagram leaving the tensioner pulley for last. Keep tension on the belt with your hand to make sure it doesn't slip off of any of the other pulleys. Once you have it routed around all the other pulleys rotate the tensioner clockwise again and slip the belt on. Make sure it's on all of the pulleys correctly before starting your vehicle again. If the belt is not on a pulley correctly you can make adjustments to the belt by rotating the tensioner pulley just enough to loosen the belt and not enough for it to slip off.
Less me know if you need any more help.
