This is pretty easy to do, as is the same in Inventor/HSM.
Rough it out (3-d adaptive is good for this) with an appropriate stock-to-leave for the final cut finishing cut.
The slope: The tool needs to be selected as a 45 degree chamfer bit with geometry defined to match your bit. Use care setting up the tool geometry, as if it is incorrect, the result will be less than good. It is possible a sample tool will match, but I doubt it. Use 3-d contour and select the bottom edge as your machining boundary. You can work with the stepdowns as needed, but if the proper tool geometry is set, it should be automatic.
If you are having difficulty in getting the tool Exactly where you want, be sure your top height is set to MODEL top, and then offset by -0.0001 or so. not enough to make a difference, but enough to get the path generation to only look at the slopes, or it will use the stock height. Also set the machining boundary to your model boundary. The flat depression at the rear of your model might require you to do this in two operations, one top to the flat area, the other the flat area to the bottom. You can do this by copying the operation and adjusting the top and bottom heights. That little tiny offset does the deal for you.