Hi Cindy,

To do this, you'll have to dig into the css of your website (here's a great place to start if you haven't done this in NationBuilder before). If you already have a custom theme, go to Website > Theme > Custom theme > theme.scss > .site_logo_header and comment out line 343 - this should set the alignment of your logo to the bottom of the banner. 

Note: This may affect how your site displays on a mobile device, especially if you've modified your theme in other ways - just a friendly reminder to test it out!