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 instructions for proper placement. I. Hey, in this article we are going to see the Single Phase Distribution Box Wiring Diagram and Connection Procedure. A distribution board or distribution box is where the main power supply is distributed to multiple loads. Preparation WorkTools and Materials - **Tools**: Screwdriver (crosshead/slothead), voltage tester, electrician's pliers, wire stripper, tape measure, marker.