how to remove the audio unit from 94 323?
 

Hi all,
I just got a new 94 323 and would like to remove the old audio unit so that I can install a new one.
I am a complete newbie on this... and judged from my internet research, it seems to me that DIN tool is not appropriate here (am i right? as to be honest, being the 9th owner of this baby, i am not even sure if that audio unit is the genuine one or not! =) )

So i tried to remove the trimpanel around that unit off.

After loosing the drawer as well the trimpanel underneath the steering wheel, I managed to unscrew 4 screws on both side of that trimpanel beneath the AC unit. Then I figured out that panel still couldn't be removed... and it seems to me that to achieve what I want to do, I need to remove the hard-plastic trimpanel over the air vent, i am really not sure... so I stuck here...

Any hint please? pictures/videos will be great!!

many thanks folks!