Those who buy Master Lock combination locks receive the lock with a combination of 0-0-0. For security purposes, you would be wise to change the combination code to something different. Those who want to be extra careful to make sure the lock combination is not compromised can periodically change the combination.
Adjust the dials so that the current combination shows in the window.
Pull the shackle straight up. Turn it 90 degrees counterclockwise so that the shackle's notch aligns with the notch on the body of the lock.
Press the shackle down into the body and turn it counterclockwise another 90 degrees.
Set the dials to any new combination you choose.
Rotate the dial 180 degrees clockwise, back to its original position. You have now reset your Master Lock.