Dell 3130cn Color Laser Printer - Manual (Page 235)

Removing the Network Protocol Adapter
1. Turn off the printer and unplug the power cable. Then, disconnect all cables from the back of the printer.
2. Turn the screw on the control board cover in a counter-clockwise direction and open the cover.
3. Remove the network protocol adapter by releasing the adapter's hooks.
4. Close the control board cover and turn the screw clockwise.
5. Reconnect all cables including the power cable into the back of the printer and turn on the printer.