I've never messed with those connectors but I'll try to help. You said you pulled off a clip from the black connector. Is there a part of the black connector that might slide towardswhere the clip was? I think the part of the black connector onthe side towards the yellow line will slide in over the rest of the black connector and while holding that in, you should be able to pull theyellow line out faily easily.
Like I said, I've never worked with those before, and I can't see the connector very well but it's worth a shot. If that doesn't work, then try to figure out why the clip was there. It had some kind of purpose.