"Unammend" it through legal channels? The Constitution can only be amended through Congress and the States. Are you honestly saying you want to subvert the democratic process to alter the CONSTITUTION? That, my friend, is an incredibly dangerous precedent to set, if it could even happen lawfully, which is doubtful. What happens when the politicians think the rest of the Bill of Rights needs updating, or that the President really shouldn't be limited to just two terms, or that the 14th Amendment has become an anachronism.
By saying that the Constitution doesn't say what it really says (a right to bear arms), and does say what it doesn't (gay marriage, national ID card, etc.), you open up all kinds of terrifying possibilities for government abuse and tyranny.
I suppose it's possible that all you meant was that the Supreme Court could rule on the matter again, but if these future Justices have any kind of ethical fortitude they will support the precedent set by this Court and not rule for purely political reasons. The Constitution doesn't change unless it is actually changed.