Dell PowerEdge 850 - Manual (Page 130)

2. If applicable, remove the optical drive.
Remove the optical 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 daughter card. See Figure A -3 for the location of the daughter card 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 6 -2 .
5. Slide the hard-drive carrier backward and lift the carrier out of the chassis.
Figure 6-2. Removing the Hard-Drive Carrier
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 6 -3 .
Figure 6-3. Removing the Hard Drives From the Drive Carriers