Find the center of the clock face using the ruler and make a small dot at this point with the pencil.
Stack the hour hand and the minute hand together with the hour hand on top. Align the squared ends of the hands precisely.
Insert the pointed tip of the brad about 1/2 inch from the end of the hands, centered between the other two opposite edges. Push the brad through both layers of paper until the head of the brad rests on the hour hand.
Insert the pointed tip of the brad through the clock face at the pencil mark. Push the brad through until the underside of the minute hands rests on the clock face.
Turn the clock face over and separate the two metal prongs of the brad. Fold the prongs flat in opposite directions.
Test the hands to make sure they move freely. If the hands do not move freely, loosen the folded brad prongs slightly.