I've read his doc (very, very helpful) and he is helping me. I just started taking the cage out until I dropped it. I just cannot allow to have the car standing in my driveway right now and would rather not mess up anything. It's very tight in there and could take hours and hours to take out and slide back. Therefore, I don't know the harness situation yet.
However, it looks like the same case as Euro / UK cars from an earlier thread that SVXdc gave me:
http://www.subaru-svx.net/forum/show...t=33067&page=2
The actual situation now:
Normally, a plastic piece just rests on the top (not attached, just resting). The lower black piece is prying/supporting the HU somewhat upwards. It doesn't look to be the original bezel, at least not in full form. For the top flange, where the screws are, I need more than just cardboard. I hope a flathead or hard plastic something can help me remove the cage without making more scratches.