I need help with unplugging the connector from the heated oxygen sensor in the right exhaust manifold on the 5.0 engine in my 2011 full size RR. I have the right head ready to remove and I removed the little sheet metal cover over the connector, but I cannot seem to be able to split this connector to the O2 sensor. With other connectors in this vehicle that I have encountered, I have carefully examined each one, and figured out where to squeeze or spread to unplug the connectors without damage. But, I can't seem to be able to get this one apart. I would appreciate advice from someone who has done this before.