What process should be followed when a law must be made fairer or more up-to-date?

Amendment

Explanation:

An amendment is a formal modification made to a law, statute, constitution or legislative bill. The next steps must be followed: two-thirds of the members of each house of Congress must approve it, and three-fourths of the states must ratify it. Then, the Congress is the one who decides if the ratification will be by state legislatures or by popularly elected conventions in the several states. Proposed amendments to a state constitution must be approved by the voters in a popular referendum in most of the states.