Murder is a bit harsh. I say have a kangaroo court first, followed by a tour of public shaming and contrition around the country. Those who plead for mercy spend the rest of their lives in chains working in the fields to feed the rest of us, the stubborn ones meet Saddam Hussein. Start with anyone with 10 figures in their bank accounts; though, sadly, even if we did one trial a day, it would still take 3 years to get to them all just in the US alone. The trials would make for good TV and a morale boost during the transition.
Mao already showed us how to take care of landlords (and prosperity gospel preachers).