I'm currently creating a new template for a client. Their current template does not implement menus at all. They are all hard coded links in the template. The new template I making them will implement the menu functionality. Their menus are fairly extensive (around 50 links). Since the menu option does not currently show up on the existing theme, how can I go about adding all the menus before I make the new template live for all visitors? I really want to minimize downtime. I know I could just take the site offline, but that's not really an option for me.