// Remove the default header
remove_action( 'genesis_header', 'genesis_do_header' );

// Add custom header
add_action( 'genesis_header', 'sk_do_header' );
function sk_do_header() {

	echo '<img src="http://66.147.244.118/~mirjavah/windborne/wp-content/uploads/dynamik-gen/theme/images/windborneheader.png" />';

}