They have nothing to do with the amending process, true. That is a function of congress.
But they do hold the sole ability to reinterpret the intent of the framers in constitutional questions.
I believe Stevens used the word "repeal" just to get their attention, and his intention was to wake them to the idea that the amendment is not clear in it's meaning.
I think the current (and past) interpretation is fairly clear. Individuals have a right to own a gun subject to government regulations. Federal and state legislative bodies determine what those regulations will be. That should satisfy everyone except those who want to ban guns or have no regulations--both representing a very small, insignificant, number of people. Even those who claim the right is limited to militia membership does not prevent others from owning firearms unless those legislative bodies outlaw that ownership which we both know they will never do.
What more do we need to know?