I did a quick search and didn't see a thread I could add this to, so below is how to swap the button controls on your COMAND head unit.

BLUF: If you buy a used COMAND head unit with the same buttons as your car it should swap right in UNLESS your car has Night View assist, then you'll need to 1- make sure your donor unit also had Night View Assist or 2- swap over the buttons.

I bought a used COMAND unit off eBay with the same buttons as my car and swapped it over. Everything seemed to work including the heated seats and the other "accessory" buttons. Later I realized my Night View Assist stopped working. I checked the fuse then used a code reader to look at values for the system. I saw that the camera, switch, and system looked fine but that the COMAND unit was not sending video signal to the screen, it then dawned on me that you do need to make sure the COMAND unit supports/is coded for Night View Assist because the signal passes through it to the screen, even though the Night View button is located by the headlights.

I removed the donor eBay unit from my car and took the buttons off that and put them onto my original COMAND unit, now I have nice buttons and full functionality.

Steps
After you remove your COMAND unit:

1- Remove bottom trim piece by gently pressing tabs outward then slide the piece out of its grooves down and to the back of the unit (when facing from front).
2- Remove 4x T20 screws (Black) from the "Accessory" button unit with heated seats, rear screen etc.
3- Remove 4x small Phillips head screws from the main upper COMAND button unit
4- Gently pry all plastic tabs (3+ top, 2xon side, 2xon bottom) to release COMAND unit buttons to the front.
5- Swap good buttons over to your original unit and reinstall