Dell OptiPlex 3020M Owner's Manual page 14

6. Perform the following steps as shown in the illustration:
a) Prepare the wooden table by installing screws for mounting the optical drive console.
b) Align the slots on the optical drive console with the screws on the table and slide the optical drive console and lock it.
c) Tighten the screws to secure the optical drive console to the wooden table.
7. Install the antenna to the optical drive console.
14 Installing the Accessories