Removing the plugs on the Central Electric Board can be challenging. The upper hook on a connector breaks off easily as our cars are well over 25 years old, and the connector seems latched at the lower side as well. I never knew where this little red thingy was for, tried to push it with no spectacular result...
Well, a friend old me: if you pull it towards you (up) the latch at the lower side releases. It is like a big strip that moves a few mm to the side, just enough to unlock all connectors at once. This makes the connectors go out more easily. Still... careful with the hook at the upper side. They do break as time makes them brittle.
Regards, Theo
1992 Porsche 928 GTS midnight Blue