Next simply create a PCB outline shape by deleting all the details that aren’t part of the outline. A little scaling here and there to get the dimensions correct and you’re done with the first ...

[rahmanshaber] used FreeCAD to get the outline of each part from the 3D model of his PCB, and KiCad to design the cutouts; skip to 7:30 or so in the video below if you don’t need the design lesson.