Dell OptiPlex 960 (Late 2008) - Manual (Page 110)

Power Cable Connectors
Connecting and Disconnecting Drive Cables
When removing an cable with a pull-tab, grasp the colored pull-tab and pull until the connector detaches.
When connecting and disconnecting a SATA data cable, hold the cable by the black connector at each end.
Removing Drive Bay Inserts
If you are installing a new drive:
1. Perform the procedure Before Working on Your Computer .
2. Press the insert retention tab on the inside of the bezel to release the drive bay insert. Remove the drive bay insert from the front of the bezel.
1 data interface cable connector 2 SATA interface connector
1 power cable 2 power input connector
1 retention tab 2 drive bay insert