Dell OptiPlex 755 User Manual page 115

1 data cable 2 hard drive system board connector
6. Press in on the blue release tabs on each side of the drive and slide the drive up and out of the computer.
1 hard drive
Installing a Hard Drive
1. Unpack the replacement hard drive, and prepare it for installation.
2. Check the documentation for the drive to verify that it is configured for your computer.
3. If your replacement hard drive does not have the plastic hard drive bracket attached, remove the bracket from the existing drive by unsnapping it from
the drive.
1 hard drive
4. Snap the bracket onto the new drive.
2 release tabs (2)
2 hard drive bracket
3 power cable