There are no illustrations in the manuals that show the exact pinpoint location of the square hole; it will be located in the tensioner arm (the arm is only about 3 inches long, so that narrows it down quite a bit). The lower illustration shows the breaker bar in position, perhaps that might be helpful.
If you still cannot see how the arm rotates, it might be helpful to jack up the right side of the car, remove the RF tire and belt splash cover, which will allow you to see the entire bottom section of the belts...