Angled Cut on an Angled Surface

I am looking to make a cut on my design watch similar to that of the one in the picture shown. I am not entirely sure how to create the cut on the lug of the watch on a curved surface and have it go up and connect in the corner like the visual shown.  I have tried draft but thats allowing me to have the points meet at the top. Ill attach the part below as well. Thank you for help!

SolidworksImport export