What you’re talking about has happened in the Communist countries (but never in the Soviet Union to our knowledge!) a handful of times since 1945, you can count them on the hands of one and a half hands. The Communists have got the tools and mechanisms of power all figured out, just look at Cuba and Venezuela and Zimbabwe, why do you think it is such a popular method of power?! (NOTE: According to an hour long video presentation on Youtube by an American living in South Korea and studying NK, NK is not really a communist state, but it has adopted some of the methods of communism.)
Post 15
Well, speaking of the Soviets, there is the story of Beria snuffing Stalin with a pillow over the face in 1953. Then Beria and two or three more Premiers went in rapid succession before Kruchev.