I stuck a piece of sellotape over the holes in the dial and the hands so the cardboard would not tear.
Put the elastic band through the holes in the button on the front of the dial, then put both ends of the band through one hole in the hands and the dial, in the end put the ends of the band through the holes in the second button and the back of the dial. Otherwise the hands won't turn :)
Tie the elastic band. You can even sew it to be sure that it won't open.