Center Genesis Header / Logo Image

Text Header

For centering the text header, you have to remove the header widget area using this snippet in your functions.php:

unregister_sidebar( 'header-right' );

Next step is to center the text, adding this to the .title-area in your style.css:

.title-area {
    text-align: center;
}

Image Header Version

If you want to center the image header, you have to remove the right header widget area using this snippet in your functions.php:

unregister_sidebar( 'header-right' );

After removing the right header widget area, you have to increase the width of the .title-area:

.header-image .title-area {
    [...]
    width: 100%;
    [...]
}

The logo image should now be centered.