Dell PowerEdge SC1425 - Manual (Page 56)

Remove the CD drive if you are removing hard drive 0. See " Removing the Optical Drive ."
3. Disconnect the power and interface cables from the hard drive.
The interface cables for SATA hard drives are connected to the system board. See Figure A -3 for the location of the system board connectors.
The interface cables for SCSI hard drives are connected to a controller card.
4. Loosen the captive screw that secures the hard-drive carrier to the chassis. See Figure 7 -2 .
Figure 7-2. Removing the Hard-Drive Carrier
5. Slide the hard-drive carrier backward and lift the carrier out of the chassis.
6. Using a #2 Phillips screwdriver, remove the four screws that secure the hard drive to the carrier and remove the drive from the carrier. See Figure 7 -3 .
Figure 7-3. Removing the Hard Drives From the Drive Carriers