Masterlock is a company that manufactures various types of locks. Some of the locks require a combination or code and others require a key. Masterlock also manufactures a line of set-your-own-combination locks. These are the only types of Masterlock locks that can be reset. In order to change or reset the combination, you will need to have the old combination. If you do not have that, you will not be able to reset the lock.
Enter the old combination into the lock. The combination is a series of three single- to double-digit numbers.
Pull open the lock. This will remove the shackle from the housing unit.
Pull the metal end off of the lock. The metal end is the piece in back of the numbers.
Slide all number wheels from the lock.
Place the wheels back onto the bar so the desired combination aligns with the "Master" logo.
Snap the metal end cap back into place.
Place the shackle back into the housing unit. The shackle should not lock into place while the combination is being displayed. Roll the number wheels. The shackle should now lock into place.
Open the lock with the current combination. Pull the shackle out of the housing unit.
Pull the metal end cap off the lock. The metal cap is located in front of the number dials. After the end cap is removed, removal all of the combination wheels.
Place the wheels back onto the lock, making sure the combination you want is aligned with the red guideline on the front of the lock. Do not turn the wheels once they are placed onto the lock, they should be placed onto the wheel with the proper number facing forward. The last combination number will be on the wheel that is placed on the combination first, with the first number of the combination being on the wheel that is placed last onto the lock.
Snap metal end cap back into place. You may hear a snap or pop when it is secure.
Place the shackle into the housing unit. The shackle will not lock because the combination is still on the dial. This indicates the code is reset. Move the dials around and the shackle will lock.
Align the three combination wheels so the preset code of 0-0-0, or your current code, is visible in the viewing windows.
Pull the shackle upward and rotate it 90 degrees in a counterclockwise motion, so the shackle rests on the notch in the lock body.
Press the battery downward and rotate the lock another 90 degrees in a clockwise motion. The shackle will be facing the opposite side of the housing unit.
Set the three dials to the combination of your choice. Ensure the number is clearly set in the window.
Rotate the shackle 180 degrees so it is placed above the housing unit. Press it into the housing unit. The shackle will not lock because the combination is still on the dial. This indicates the code is reset. Move the dials around and the shackle will lock.