The Xbox Support page instructed Xbox One owners with a two gigabyte USB stick to download one of two compressed update files to their computers, then unzip them to the root of the USB drive. The process then had owners holding the bind and eject buttons while turning their consoles on, releasing the two buttons once they hear two start-up tones. According to the now-unavailable support page, that last step told the Xbox One to search for an update from a USB drive, a procedure that isn't part of the system's initial booting process.
We've contacted Microsoft for comment.
Update: A Microsoft spokesperson tells Joystiq that "the site was not an alternative way to take the Day One update and customers still need to connect to Xbox Live for the update. Because of the complexity of this customer support process we've actually removed the page and we will work with customers directly to make sure they have a smooth experience."