Whether you have moved into a new house or just lost your instruction manual, do not fret. Changing the code for your Sears Craftsman or Liftmaster garage door opener is a very simple task. Different methods can be used to program most Sears garage door openers. If your model is more than 5 years old, you may need to obtain instructions specific to your model.
Locate the motor unit mounted on the ceiling. Located at the rear of the unit is a button to reset the entire system. Press and release button.
Enter the new 4-digit code into the keypad and push enter. Lights should flash to let you know it has been programmed.
Push the button on the remote to ensure that it is working. You may also test the keypad entry to ensure that the new code works there, as well.
Alternate Resetting Process
If the previously described process does not reprogram your remote, try the alternate procedure. Some motor units have a "Program" switch on the back. It may be difficult to see without unplugging it. Unplug the unit before trying this option.
Flip the switch to "Program" and enter new 4-digit code into keypad.
Switch the motor unit back to "Operate."
Plug the motor unit back in. The light should flash on to signify that the reprogramming has worked.