I however think trying this, may prove itself to challengint, at least the big lid has to be removed ( been there done that already, since the cabinet was too tall for my car, it is however now re installed. The lid is very heavy and it was quite challenging in itself to re install), and the rest of the cabinet would have to be put in a certain angled position, so it can be possible to enter the screws through the motorboard. It could maybe be done, but I also fear scratching the edges of the cabinet etc. But, this was maybe how they did it maybe even before covering the cabinet with varnish etc..who knows.
I have come up today with a solution I will try tomorrow, with the help of my son: I will put strong fishing line through two holes in the cabinet, gently holding the motor as close as possible to the the correct position and then allow the fishing line to go through the two holes using a big needle from the downside of the motorboard. I will then ask my son to hold these two the fishing tightly over the motor, and this way also hold the weight of the motor, while I will then install the two screws from the top and nuts on the downside, on the last two holes that are free from fishing lines. When the these two screws and nuts are secured, the fishing lines can be removed before securing the last two screws and nuts.
