In the attached part's Cut-Extrude1 I have made a small mistake. I did not realize that I needed to make Boss-Extrude7 until much later in the drawing process. What I want to do is correct this mistake. I think the easiest way to do this would be to change Cut-Extrude1 and somehow have the starting point of the cut be at the furthest end of Boss-Extrude7. Making the cut go both ways does not work because the only way to do so is via "through all" which, as you can see, will cut through other parts of the part.
I suppose I could make yet another cut, but in the interset of efficiency, it seems better to modify the original.
How do I do this?