Clearly My Knowledge of the Legislative Process Is Sorely Lacking

An interesting article in the New York Times, outlines the various proposals Democrats are now mulling over to get the troops out of Iraq. Looks like they have a few interesting options.

Hillary Clinton and Robert Byrd are proposing to "repeal President Bush’s war authorization" that "would require the president to seek new authority from Congress to extend the conflict beyond Oct. 11, 2007." The article doesn't explain, exactly how this could be done. Would they do it in the form of a bill? If so how could they keep bush from vetoing it like he did the last bill, and if not, how could this be done?