Recently, my friend sent me this link.
This page is set up to print a document requesting the reversal of a baptism. It’s actually great! In the French version, it says that you were baptized against your will (because you were too young to have any say in the matter) and legally request your name to be removed from the registry. The English version is phrased slightly differently, but still gets the message across.
Find the page here.
Et en français, ici.