As I note elsewhere, it has been done before. Stuart A Bell 2001. All information is believed correct, but no responsibility whatsoever can be accepted for any consequences arising from your reading of this site.
All work is done at owner's risk.
Slide the CD drive over the floppy drive from the back, mark where it meets the front panel, and from the front, cut out a suitable aperture. The speaker will have to be moved. From the side, you can see the CD drive sitting above the floppy. The CD drive in situ, with the tray 'out'. One 'bar' of the 'grille' is shortened to leave access to the eject button.