The answer to the first part of the question as asked: a complete change of organizational structure and charter.
The General Assembly consists of all member states of the United Nations; each has an equal vote. However, all resolutions of the General Assembly are non-binding, meaning that compliance with them is completely voluntary and that there are no penalties for non-compliance and thus no method of enforcing a resolution.
The only part of the United Nations with the ability to enforce decisions is the Security Council. There are 15 members, but they are not equal in authority. Five of the members are an elite group known as Permanent Members. They are the United States, the United Kingdom, France, China, and Russia.
The five permanent members of the Security Council are elite because each possesses veto power. That is, any resolution of the Security Council can be vetoed by the action of a single one of the permanent members.
So, five nations determine whether enforceable resolutions can pass: but any one of them can veto any resolution. There is no ability for the General Assembly to impose its decisions. There is no way for the Security Council at large to impose its decisions. There is no way for a majority of the five Permanent Members of the Security Council to impose their decisions.
Finally, the Security Council only passes resolutions dealing with a breach of the peace between member states. It has no authority to pass economic, environmental, trade, or domestic criminal or civil laws. Its only judicial body is limited to adjudication of international war crimes; but its enforcement powers are weak.
The design of the United Nations thus suggests that the founding Permanent Members of the Security Council had no interest in creating a world government with jurisdictional and enforcement authority over member nations or with any ability to supercede the sovereign powers of individual members. It also suggests that the founders did not consider the United Nations to be a vehicle for enforcing coercive power over each other. Rather, it was a method of enforcing the peace over the rest of the member states, in those cases where all five permanent members agreed on a course of action.