You can just place it inline with the ignition switch power feed. Or any power wire that prevents starter from getting power. Some of the kill switches are for the neg battery cable. You don't have to go that nuclear unless you want to. You can cut off the whole truck's neg or just the ignition power.
That style is not quite right for a hidden power disconnect switch as I describe, because it's terminals are unprotected. Exposed to shorting. The one's that attach to the neg battery won't have a shorting problem. But that is the only place to kill negative becasue the rest of the "negative" path is the whole chassis. So if you want to do a power cut off, keep that terminal protection in mind. Maybe a more simple, less robust toggle switch can be used for the power disconnect.
As you know, it's all about how you mount it securely. All the the dash switches that have power to them have terminals sticking out/unprotected. So take your clue from that and improve if you wish.
CLICK Bend up a bracket for this and hide mount it. This switch as an optional "Lock Guard" and mounting bracket.
