Your watch is equipped with an automatic movement. If it has stopped, give the winding-crown (in the push position) a few turns clockwise.
The winding-crown has 2 positions:
1 Push position = normal position for wearing the watch.
2 Pull position = position for setting the time. Pull the winding-crown all the way out and turn the hands clockwise to set the desired time. Then, don’t forget to push back the winding-crown against the case.
1 - Remove the screw on the right-hand lug by turning anticlockwise with the supplied dynamometric screwdriver.
2 - Remove the screw on the left-hand lug by turning anticlockwise with the supplied dynamometric screwdriver.
3 - Push the central pin out from between the strap and the lugs and remove the strap. Repeat steps 1-3 on the other side of the case.
4 - Place the new strap between the lugs and slide the central pin through lugs and strap.
5 - Screw-in the left and right-hand screws into the lugs by turning the dynamometric screwdriver in a clockwise direction. Take care not to force or over-tighten screws. Repeat steps 4-5 on the other side of the case.