How do I remove firewall wire harness connector 63-64 fullsize?

[BamaWildcat]

Please see attached. I am trying to remove the main electrical connector in the firewall of my parts car. It doesn't seem to have any screws that hold it in, so I have tried to push in it from one side and pull from the other. I have also tried to pull the gasket down, but that doesn't seem to get me anywhere.

Do I just cut the gasket with a knife, or am I missing the way to pop the whole thing out gasket and all?

[TXGS]

There should be some bolts in the passanger compartment that will need to be removed to get it to unplug. It will be where the engine harness plug meets the fuse block. :beer

[BamaWildcat]

No bolt heads seen on the outside or inside, no bolt threads seen on the inside or outside.