The MDC Stun/Kill option can generally only be transmitted from Dispatch Consoles - ie Centracom Consoles, and I'm not totally sure if current Zetron products support it or not, but I would not be suprised if they did. Typically, only the Console that "stunned" the radio can "un-stun" it, but if you force a matching 'good' codeplug from a good donor source radio, you can revive it. Not sure on newer radios such as the Waris and 2500/5k radios, but older first generation Astro radios are possible to revive.