Dell OptiPlex G1 - Manual (Page 68)

To remove a 5.25-inch drive assembly from the middle or lower drive bay, follow these steps:
1. Disconnect the DC power cable and the interface cable from the back of the drive.
2. Press in on the two retaining tabs (one on each side of the drive), and slide the drive assembly forward to remove it.
3. Remove the four screws attaching the 5.25-inch drive to the mounting plate, and lift the drive out of the mounting plate.
When you replace the 5.25-inch drive, align the front of the drive flush with the tab at the front of the mounting plate. Insert the four mounting screws, and tighten them
in the order stamped on the bottom of the 5.25-inch drive-mounting plate.
Hard-Disk Drive Bracket Removal
To remove the hard-disk drive bracket, follow these steps:
1. Disconnect the DC power cable and the interface cable from the back of each hard-disk drive installed in the hard-disk drive bracket.
2. Remove the screw that secures the hard-disk drive bracket to the front of the chassis.
3. Grasp the handle on the front of the bracket, and rotate the front of the bracket upward until the hooks are free from the chassis.
4. Lift the hard-disk drive bracket out of the computer.