Sometimes you need to do to following things with footer:
1. Need to remove footer support from theme
2. Need to remove footer
3. Need to add custom footer HTML
So here is an example to for all above option.

1. Need to remove footer support from theme

/** Remove footer widgets support from theme */
remove_theme_support( 'genesis-footer-widgets', 3 );

2. Need to remove footer

/** Remove Footer */
remove_action( 'genesis_footer', 'genesis_do_footer' );

3. Need to add custom footer HTML

remove_action( 'genesis_footer', 'genesis_do_footer' );
add_action( 'genesis_footer', 'custom_footer_html' );
/**
 * Custom Footer HTML.
 */
function custom_footer_html() { ?>

	<div>
		 <!-- Your Copyright text goes here -->
	</div>
<?php } ?>