Replacing Site Tagline on Pages in Minimum Pro with Custom text using Advanced Custom Fields. http://sridharkatakam.com/how-to-replace-site-tagline-on-pages-in-minimum-pro-with-custom-text-using-advanced-custom-fields/

gistfile1.php

printf( '<div %s>', genesis_attr( 'site-tagline-left' ) );
printf( '<p %s>%s</p>', genesis_attr( 'site-description' ), esc_html( get_bloginfo( 'description' ) ) );
echo '</div>';

gistfile2.php

printf( '<div %s>', genesis_attr( 'site-tagline-left' ) );
$tagline = get_bloginfo( 'description' );
if ( is_page() && get_field('custom_site_tagline_text') ) {
	$tagline = get_field( 'custom_site_tagline_text' );
}
printf( '<p %s>%s</p>', genesis_attr( 'site-description' ), esc_html( $tagline ) );
echo '</div>';