What do you do if you are a Catholic and no longer want to be a Catholic?

How you leave the Catholic Church depends on where you live. In some places you must register with the government so you cease paying a church fee. In the United States, you simply stop going. Unlike Protestant Churches, The Catholic Church does not keep a membership roll. If the priest comes by to ask what happened to you, you simply tell him that you left the church. (You leave a Jewish Synagogue by not paying your annual fee.)