Set of 3 tools to disassemble your HEWLETT-PACKARD HP01 LED Calculator Watch. 

1. Use back_cover tool counterclockwise to remove the cover. Remove the batteries.
2. Use inner_inner_ring tool counterclockwise to remove the first ring. This will release the plastic battery holder assembly. Be careful about the springs.
3. Use inner_outter_ring tool clockwise to remove the second ring. When the ring is loose, find the split and pull and twist to remove the whole ring, unlinking the two parts of the body of the watch