Blasted electric connector

I am changing spark plugs on my 2019 Tacoma, 6 cyl. I have the passenger side done. I am stopped by one lousy electric connector over the middle plug on the driver side. I have half of the fixture disconnected but the second half is sitting on some kind of post mounted to the engine and I can not see how to release it. I have tried everything I can think of for 4 hours. Anyone know how this thing releases. HELP!!!!

 

@caribe makaira may have clue.

 

A couple of suggestions:

1. Find a similar connector in a more accessible location and practice on that.

2. Sometimes even when you press the release tab, the lock does not release. See if you can get a pick tool under the lock to hold it open while you separate the connector.

3. Sometimes the connector doesn't seem to want to come apart even when you're sure the lock is released. Try to use a mini pry bar to gently pry apart the two halves of the connector.

 

Pics?

 

I just changed the plugs on my 2018 about 5K miles ago. If it is the middle plastic post, I am thinking of it pushes in and then pulls up to release. Then you can get to the driver's side plugs. Good luck?!