Check to see if you still have the wires leading up to the handlebars for the kill switch. The kill switch is usually missing because it was smashed in a fall but the wires can still be there.
If you have the existing wires then you can replace it with just about any kill switch by splicing into the existing wires.
If the wires are not there then it would be a lot easier if you got a kill switch that came with the right length wires with the proper connector to attach to your bike's wiring harness. There isn't any rocket science to a kill switch, and other than the connector it doesn't have to be make, model or year specific.
Rod