How do you install a killswitch on a 407777 Briggs engine?

To install a killswitch on a Briggs & Stratton 407777 engine, first, locate the ignition coil wire connected to the spark plug. Cut the wire and connect one end to the killswitch terminal, then connect the other terminal of the killswitch to a good ground point on the engine. Ensure that the killswitch is rated for the engine's voltage, and secure all connections properly to prevent any short circuits. Finally, test the killswitch by starting the engine and then using the switch to ensure it stops the engine as intended.