Dell OptiPlex 3000 Tower Service Manual page 78

Steps
1. To remove the dummy metal bracket, insert a flat-head screwdriver in the hole of the bracket, push the bracket to release
the bracket, and then lift the bracket out from the system.
2. Insert the optional Serial module into its slot from the inside of your computer.
3. Connect the Serial module cable to the connector on the system board.
4. Replace the two (M3X3) screws to secure the optional Serial module to the system.
Next steps
1. Install the front bezel.
2. Install the side cover.
3. Follow the procedure in
78 Removing and installing components
after working inside your computer.