That is the way these gibs look, you are looking at the end of the gib. It has a notch in it where the screw comes up and pushes it upward. Support the head with a block. Then remove both the top and bottom gib screws and you should be able to push the gib down from the top using a small rod to remove it. You will then see what the gib really looks like. I have done this several times on my 940V, it is quite easy.