This procedure is commonly performed to replace clock batteries.
Place your hands at the 10/11 and 4/5 positions.
Turn each clock counter clockwise to unlock the clock housing from the twist-lock mount.
Reassemble clocks to bracket.
Place clock in the housing with the 10/11 and 4/5 numerals over the brass posts.
Place your hands at the 10/11 and 4/5 positions and turn the clock clockwise to lock into place.