Shut off the power to your garage door's automatic opener hardware via the main "Power" button on the ceiling-mounted head unit or via the circuit breaker panel in your home. In some instances, the head unit's power cord is situated where you can reach it, and you can pull the plug from the wall outlet to turn off the opener.
Place a ladder underneath the garage door head unit.
Check the mounting screws or bolts that secure the protective housing over the motor. Make sure they are securely in place. Check the housing to make sure it fits evenly over the motor. If it isn't, proceed to the next step.
Remove the screws or bolts with your screwdriver or wrench.
Remove the housing to expose the motor. Fit the housing back over the motor, making sure that the housing fits flush over the motor and the sensor on the front of the motor is exposed.
Replace the screws or bolts in the housing.