A classic f/1.2 Rokkor from 1970 is modified to fit directly on the Maxxum 7D.
The MC lens mount, aperture link ring, link bearings and mount spacer are removed.
A standard Maxxum T mount is turned to the same thickness as the removed mount spacer.
Holes are drilled in the turned T mount, using the old spacer as a template.
The new mount is substituted for the old mount and spacer using the existing
screws and holes in the lens body.

Addendum:

Since starting this gallery there I have reluctantly converted a dozen or so of the Rokkors to the EOS mount because of the demand. All are non destructive and can be returned to the Minolta mount as they were originally made. I cringe at the numerous hacks to this fine lens that involve "sanding" of the spacer ring and other destructive modifications.

No aperture lever is used in the modification. Lens is simply used in the "stop down" mode.
I usually just set the camera in the "A" mode and let the camera pick the shutter speed.
This arrangement works surprisingly well.

Depth of focus is very shallow at f/1.2 and lens must be focused carefully by eye (manually).

All the parts removed can be put back for continued use as an MC lens.

The restyled 58mm f/1.2 MC lens with the rubber focus ring has identical construction in the mount area, so this modification will work with that lens too.

A few other MC/MD lenses can be similarily modified, though almost all have equivalents available in the AF mount.