Dell OptiPlex Gxi - Manual (Page 101)

Front-Panel Insert Removal (Low-Profile Chassis): OptiPlex GXi
1. Lay the computer cover upside down on a flat work surface, with the front of the cover facing you.
2. From the front of the cover, use your thumbs to push inward on the insert until it slides off the two posts.
To replace a front-panel insert, position the front-panel insert, and then press the ring-tabs over the posts. If necessary, use a 1/4 -inch nutdriver to secure the ring-tabs.