HP -01 Owner's Manual page 79

1. At the end where the band links are hinged to the buckle,
unfasten the hinge pin by pressing it with a sharp pointed object
(pin, knife point, file tip, etc.).
2. Move the pin along the buckle to the appropriate adjustment,
and snap it into the pin holes on the side of the buckle.
For most people, this simple clasp adjustment will eliminate the slack. However, if your HP-01
still fits loosely, you can remove a few links from the band. We advise letting your dealer fit you if
link removal is necessary.
If you are not near a dealer, follow this procedure to remove the links yourself:
Maintenance and Service 77