Garage Door Opener How To 1. How to program or reprogram a Chamberlain Craftsman, or Liftmaster garage door opener transmitter or remote control to your garage door opener. 2. How to program a Genie Intellicode or Overhead Codedodger garage door opener remote transmitter. 3. How to program a built-in sun visor transmitter to a garage door opener. (Opens Homelink.com site in new window) 4. How to program or change the code on a Chamberlain, Craftsman, or Lift-Master garage door opener keyless entry code pad. 5. How to check and adjust the garage door opener photo cell sensors. 6. How to control the garage door opener lights from the remote control transmitter. 7. How to know what the flashing LED lights on your garage door opener mean.