Well, now my problem is the stupid ECU harness at the passenger footwell. I think the passenger seat is back all of the way, but I'm not sure. It's super awkward trying to contort myself in there. I can squeeze the tabs on the bottom one enough to get an audible click, but the connector isn't budging. Very frustrating.

 

The seat may not be back all the way. I found it very comfortable working in that area.
CRC makes an electronic contact cleaner which is safe for most plastics. It may help you clean and lube the connection to ease disassembly.

 

If you are trying to disconnect harness at ECU, as memory serves only one connector, the one on the end has the click type connection. The rest have a small release button with a lever type pull. The lever lifts the connector off the ECU port.