More information: Laws can be changed in several ways. One is where subsequent legislation changes or amends specific portions of the law. A second is where subsequent legislation repeals only specific portions of a law.A third is where subsequent legislation repeals an entire law and replaces it with a new version of the law. Laws are made by the congress sending a bill to the other congress people and then to the president and he can either veto the bill and send it back and not made a law.. â¦ ..or he can approve it and send it to all the other like legislative branches and stuff like that.