Changing the entire code of laws with the current amendment laws, is not only reasonable, it's necessary.
An amendment is the act of formally altering a document. As such, the amendment process is the process by which we alter a document (the Code of Laws). Now, you could say that we are not altering the Code of Laws, but removing it.
That, however, would be wrong. The document itself will remain, the contents is what will be altered.