I see all the memes about guillotines for the rich, funny in spirit, but actually building one in the town square is not practical. They take a ton of materials, they are huge, and they do not even work reliably. Would it not make more sense to build one from metal with hydraulic pistons or something? I am not a machinist, but a more mobile unit you could wheel into a square to decapitate a few effigies seems about as effective for sending a message, and easier to remove or relocate if needed.
If we’re being actually realistic I think it’s “tax the rich so that they are no longer so extremely rich, and use the resulting funds to benefit the general population.”
There’s no need for killing.