Question: how to program a liftmaster remote to a chamberlain garage door opener?
Answer: Step 1: Locate the Learn button on your opener. ... 
Step 2: Press and release the Learn button (press and release twice if your LiftMaster opener is equipped with a MyQ Control Panel).
Step 3: Within 30 seconds, press and hold the button on your remote control that you would like to program for three seconds.