Dell OptiPlex 330 User Manual page 54

b. Attach the screws to the new drive.
5. Align the shoulder screws on the optical drive with the shoulder screw slots, and slide the drive into the bay until it clicks into place.
1 optical drive
3 shoulder screw slots (2)
6. Connect the power and data cables to the drive.
7. Connect the data cable to the system board connector on the system board.
1 power cable
3 optical drive connector
8. Check all cable connections, and fold cables out of the way to avoid blocking airflow between the fan and cooling vents.
9. Replace the drive panel by aligning its hinges and rotating it up until it snaps into place.
2 shoulder screws (3)
2 optical drive data cable