How to disconnect fusebox connector?

How can I disconnect this connector that goes into the engine bay fuse box ?



I understand there is a connector that can be unplugged inside the fuse box but what I don't know how to do is disconnect the hookup above from the rest of the box but does seem doable as the flat part above the socket does seem like it can be detached from the sliders on either side.



The reason I want to do this is remove the cable that has FI connectors, which is blocking my access to the left side cylinder head.