How can I reset every code on the garage opener?
Sold my car today and the homelink had a code to open and close the garage door.
What do I have to do to reset the door opener? I don't want the guy who bought the car to come back and get something out of the house.
Thanks,

I think many, if you press the "learn" button for a couple of seconds, you can add a transmitter, if you keep holding it may erase all.
It would be good if you still had the car to test. If you asked him to bring back the car to verify it is erased, he could just remove the battery?

It varies from model to model but most can be reset but not all. It is far easier to get the homelink to forget than to reprogram the opener but too late for that. What brand and model opener do you have?