The code to do this should be inside your functions file and it looks like this –
// Reposition the Secondary Navigation
remove_action( 'genesis_after_header', 'genesis_do_subnav' ) ;
add_action( 'genesis_before_header', 'genesis_do_subnav' );<!--formatted-->
You can change it to “genesis_after_header” and it will show up after the header…..you could also just remove that code alltogther and I think it will show up right after the nav by default. Let me know if that helps