Dell 5100cn Color Laser Printer User Manual page 68

3. Remove the three screws on the controller card from the back side of the printer.
4. Remove the controller card from the printer by the handles.
5. Place the controller card on the table so that its edge hangs over the edge of the table and the controller card is
horizontal. Hold the multi protocol card so its connector is aligned with the slot on the controller card, and push it
down.