This is no doubt a REALLY dumb question, but I am baffled as to why I can not pull apart the wiring connection plugs that go to the distributor. I found another similar plug under the hood, similar to the largest one adjacent to the distributor. I depressed the small rectangular button, and it clicked. Making sure the button stayed down, I could not pull the plug apart, but wedging a flat screwdriver between the two plug halves got it moving, and then it would come apart. Trying the same on the distributor plugs just results in bending and breaking plug plastic. Spraying with WD-40 has no effect. What now? - Phil