The school pulldown is in the wrapper header. The wrapper header is a district module, and must be edited from the Admin Center. Same with the bottom wrapper.
To edit the schools pulldown in the wrapper above, you must be a Senior District Webmaster. Go to the Admin Center, and click the District Modules Tab. Click edit and select the item you want to edit. Changes will occur immediately on all sites that that use this overall theme (so any template in the theme).