Every single person hits that - after you follow first step and push opener button in front of your car them you need to climb to the device in your garage, find that red button in it, press it then RUN back to your car and press something there - read car manual again, it is very vague in description but generally correct.

I looked somewhere in internet for detailed instruction about this process as car manual did not make much sense on what exactly to press where at what moment. google it - i found it pretty quick but completely forgot where it was.

 

Here are the steps to program Homelink buttons:

1. Press one of the Homelink buttons in your car
2. Go the front of the car, push the garage remote until the turn signal light flashes
3. If your garage opener has rolling code, find the Learn button (usually Purple color) in the back of the opener and push it, then go inside your car and push that same Homelink button again. If it accepts the code, the garage opener light will flash.
4. Repeat the process for the rest of the buttons

I would add that, before step 1, press both rightmost and leftmost Homelink buttons in your car (1-dot and 3-dot) and hold them for 10-20 seconds until the light flashes rapidly. What you are doing is erasing all previous memories of the Homelink buttons and starting fresh.