function sk_change_genesis_primary_sidebar() {

	if( is_active_sidebar( 'primary-sidebar-book' ) ) {

		// Remove the Primary Sidebar from the Primary Sidebar area.
		remove_action( 'genesis_sidebar', 'genesis_do_sidebar' );
		remove_action( 'genesis_sidebar', 'ss_do_sidebar' ); // for when Genesis Simple Sidebars is active

		add_action( 'genesis_sidebar', 'sk_do_sidebar' );
	}

}