Dell OptiPlex GX50 Systems Service Manual page 23

e. Remove the screw holding the control panel to the chassis, and pull the panel up and away from the chassis.
Replacing the Control Panel and Badge
Small Form-Factor Desktop Computer
1. Replace the control panel and the control-panel shield.
2. Replace the plastic computer cover. Make sure that the two metal hooks and tabs are securely in place.
Replacing the Plastic Computer Cover—Small Form-Factor Computer