Wiring Connector?

[BFlat]

Injector wiring harness. Never seen a plug like this. How to disconnect it?
I’d like to install a new harness, but there’s NO slack in the wiring so even if I do get it disconnected I’m not sure how I’d get the new one plugged in.
Tempted to leave in the stocker.
Thanks

 

[1986 Buick GX1]

Remove locking tab (red).
Pry up at yellow arrow and pull apart.

 

[BFlat]

Locking tab doesn’t want to come out, but I’ll get it.
Many thanks!

 

[1986 Buick GX1]

Maybe you can squeeze the slotted section with a needle nose to help relieve some tension?