Actually working with the hooks is fairly simple. You just make use of remove_action and add_action.
So, you’d remove the themeblvd_header_content_default function from the themeblvd_header_content action hook:
remove_action( 'themeblvd_header_content', 'themeblvd_header_content_default' );
And then you’d add the function to the action hook that you want.
add_action( 'themeblvd_whatever', 'themeblvd_header_content_default' );
Or create your own function that displays what you want and hook it on:
function my_whatever(){
// do something...
}
add_action( 'themeblvd_whatever', 'my_whatever' );
But then simply moving this function to somewhere else is then going to require a lot of CSS changes.
Why not just remove the header content all together and then just put your Logo and Menu in the left sidebar with widgets? You could use a text widget with some HTML in it for the logo to just display an image. Then, you could use the “Custom Menu” widget to display a menu.
This is actually kind of what I did on this site, which is a Child theme of Jump Start. I set the site to have the Left Sidebar sidebar layout. I unhooked everything in the header. I hooked the themeblvd_header_logo_default function to the top of the sidebar. Then I added the custom menu widget to the Left Sidebar itself from Appearance > Widgets.