Epson 4000 - Manual (Page 87)

3. Turn the hard disk drive over and locate the four mounting
holes on the drive.
4. Position the bracket on the hard disk drive, aligning the
holes in the bracket with the holes on the drive.
5. Secure the bracket to the drive with four screws.
Note
If you plan to install two hard disk drives, you must use
flat-head screws to secure this drive to the mounting
bracket. You can purchase flat-head screws at any
hardware store; request this size: #6-32UNC x 8 FH, M,+.
Also, make sure you set the jumpers on both hard disk
drives to indicate which is the master and which is the
slave drive. See the documentation that came with your
drive for instructions.
Installing and Removing Drives 5-11