How to get this done is the age-old question.
Gotta find a way to separate corporations from their wealthy owners. Then distribute shares across society.
Corporations are a legal fiction that limits the formal liability of the shareholders in court. This, fortunately, renders them mortal.
No law of the universe says they can't be legally obligated to operate on a non-profit basis, owned and operated by communities.
So, how to impose costs on their day to day operations to the point they see the futility in maintaining disproportionate control?
I have to wonder if Lester Crest from Grand Theft Auto V isn't onto something...