Mechanical parts in metals are done in much the same way as for plastic parts.
After the first, rough PCB layout, a 3D drawing is made in SolidWorks®.
Often, a plastic model is printed as a prototype, we use a small milling machine and a smal lathe for the finishing touch-up.
A metal shop handles the production of the metal part from this point.
All documentation is done - nearly - automatically and changes are automatically updated on all drawings.