The unit was described as "not heating" or "cooling rapidly". The front panel and every other feature seemed to be functioning just fine.
I will describe how to tear down the unit, what can go wrong, what I did to repair mine and how well it works.
To get inside the unit, there are many screws that need to be undone: around 5 at the back of the unit (except the air filter ones), two below (left side with the unit facing you). Then you need to carefully lift up the plastic trim that surrounds the LCD and controls, all around, you will have two more screws just next to the airbag.
Most of the screws are Torx T20, some of them are Phillips (PH2 I think).
With those undone, you can remove the left [metal sheet] panel, that gets you access to everything inside the unit.
The main board and folding switch rest near the front-top side.
In this case, the main board was hanging by some threads and the folding switch had an ugly fix. I suspect the unit was moved with the 'mannequin' in the raised position, which places stress on all the components and can bend the very thin metal frame.