ok, this is what I do. Loosen the pivot nut, loosen the locking bolt.
The bolt is on the outside of the belt. On the inside of the belt,
close to the bolt is the square hole. I use a small 3/16 extension
(around 2 inches long) and a ratchet handle. You may have to move the
engine up or down to get it on. Then turn the ratchet anti-clockwise
to take the tensioner away from the belt. When it is at it's furthest
distance away from the belt (ie at the end of the slot) lock the bolt
to keep it there. Remove the belt. Fit the new belt in the order__
crank, static pulley, pump, cam, tensioner, water pump. Make sure
there is no slack from the crank to the cam. There should be slack
after the cam, obviously. Release the lock bolt to allow the tensioner
to tension the belt. Lock the bolt, remove the pins, turn the engine
over by hand one revolution of the cam (that would be two of the
crank) refit the pins and undo the lock bolt to ensure all the tension
is taken up. Tighten the lock bolt and the pivot nut. Remove the pins.

As far as I know there is only one hole in the flywheel. If the pump
and cam are lined up to fit their pins then the crank pin should go in
fine. If you are using the correct size pin, when it is fitted you
should not be able to move the crank. I use the Peugeot tool and have
never bothered to measure it, but I guess it is around 8mm.