That connector is like those on the injectors. Squeeze the wire clip and pull straight back. For me it took two people, my two hands with large pliers and wife doing the pulling. It was a PITA, even though I had removed the throttle body and breather box first.

I think I had to use a large adjustable wrench to get the sensor loose. Once loose, it was a finger spin to remove it.

Have the new sensor right there, and you should not loose much coolant. It goes in finger spin, but for the last tightening.

If you have the breather box off, as did I, cover the holes into the block with something so any coolant lost doesn't get into the oil pan. It won't bother things much, but it's so easy to lay in paper towels to prevent worry.

Good Luck,

Bob

:>)