Cut out on complex part

[totalhack]

I am trying to design this part and everything is straight forward except for where I need to cut out a certain area. How can I cut out the area traced in red? I read all the tutorials I can find but nothing seems to match my situation.

I have attached a picture of my design as well as the design file itself.

[Tech3]

Set Z for these regions to negative values. Note that you should use full circles adjacent to these cutouts instead of separate arcs like in your design currently.

[totalhack]

I changed those areas to circles but I still cannot get this area cut out. I have attached a second version on my design it is without the cut outs I am talking about. I included it so you can get an idea of what I want the part to look like. Except I want the cut outs of course.

Also here is a picture of the finished product that I am trying to reproduce.

[Tech3]

Take the cutouts from the first design, paste into the second design and set Z to a negative value.