Use a screwdriver to remove the switch plate cover, then unscrew the switch from the electrical box. Disconnect the wires from the old switch and connect them to the new switch, following the manufacturer's. I currently have 4 switches controlling an outside light (one at each door leading to the patio). As I have replaced the outside light with a Philips Hue, I wish to only have 1 switch. After some research the circuit I have is wired like this. Removing a modular switchboard is not that hard. This is a tricky part of the project & if you've never done this before I'll wager that you didn't even think it was possible to remove an existing outlet box or light switch box.