Dell OptiPlex G1 - Manual (Page 49)

Control Panel Removal (Low-Profile Chassis): Dell ™ OptiPlex ™ G1 Systems
To remove the control panel, follow these steps:
1. Disconnect the control panel cable from the PANEL connector on the system board.
2. From the inside of the chassis, remove the mounting screw holding the control panel to the chassis.
3. Remove the control panel from the chassis.
When you reinstall the control panel, be sure to put the right side of the control panel behind the mounting tab.