I installed this in an SE which has one floppy drive and a dead hard drive. It just barely fits using the original SCSI cable, and with the hard drive bracket still in place. If you have more room available, you could use one like TDNC's which sits further inside the case.

Requires 4pcs #6-32 threaded inserts and 4pcs #6-32 screws (you may have some on hand from modern PC cases, they're used for motherboard screws and 3.5" hard drives)

Pictured: Prusament Lime Green PLA