How do I take off this tasty looking donut?

[Deemo13]

Hey guys,

I feel like I ask like a bazillion questions, but I'm getting pretty far on my swap and trying to finish it before Sunday (bit optimistic).

I got the transmission off of my 617.952 only to find this thing. It looks like it is bolted from the motor side, so I am really confused on how it works.



I feel like I'm missing somthing blatantly obvious.

I already tried brute force. :/
Kind of looks like it has to do with this hole on the bottom of the motor, but I cant really lift it up to see.

Thanks PP, you guys are great
-Josh