I'm currently taking a class about this (kinda). The current system, which is, in the states, neoliberal capitalism (redundancy for clarity) encourages people to act immorally, or more accurately under a set of morals that justifies those actions. A different system can encourage a different set of actions to get success, and a different set of morals to justify those actions. This is a large part of politics. The other part is praxis, or getting that in place. I'm not going to share the set of theory I believe in, but rather common ways people try to impose their desired version of society.

One way is through the current system, even if you want to completely change it. This is what the class I am talking about. You identify who has power, why they act the way they do, and how you can get them to enact your policies, or at least gain power yourself. This method falls under a lot of criticism, as it stands to reason that a system built by those in power cannot overthrow them. You can't use the master's tools against him.

The other way is revolution, but that has its own problems. It is hard to convince people to completely change everything, and when it does happen, it often happens in the best way possible for those who have power. It also isn't any more moral than the other options, but that is the nature of changing an immoral system. Welcome to politics.

Disclaimer: I'm by no means an expert, as I am just getting into political theory, both in my own studies and formal education.