3 steps: 1) a Constitutional Amendment that no organization (corporation, association, group, for-profit, not-for-profit, secular, religious) has the rights of a natural person and may not contribute anything of value toward influencing elections or legislation; 2) legislation limiting the total annual amount that any individual may contribute toward political action (e.g., no more than 40 x 52 x the federal minimum wage in total to all candidates, parties, PACs, etc.), and 3) legislation requiring all political ads to be factually accurate.
This would not limit political action, moving it back to the people through volunteer action and rational, factual debate and away from the corrupting influence of money. Organizations would participate by convincing their members to act individually.