Change point lets you change any intersection point on the surface to any other point. Use the pick button and the mouse to select the point. Then type in the point’s new coordinates. The surface is redefined to maintain the overall smoothness of the surface so the shape is still tangent continuous.
This edit breaks the link between the surface and the method originally used to construct it. You can’t open the surface’s properties dialog box now and modify it based on the parameters that originally defined it as those parameters no longer apply directly to this surface.