Turn off power at the breaker
Verify power is off with a voltage tester
Remove the switch plate cover
Unscrew and pull the switch out of the box
Identify the hot wire, load wire, neutral wire, and ground wire
Disconnect the wires from the old switch
Connect the hot wire to the switch common terminal
Connect the load wire to the other switch terminal
Connect the ground wire to the green ground screw
Connect the neutral wire only if the switch requires it
Tighten all terminal screws securely
Fold the wires neatly into the box
Mount the switch back into the box
Install the switch plate cover
Turn the breaker back on
Test the switch operation