How to Hide SEO Smart Links Admin Menus

function plt_hide_seo_automatic_links_menus() {
	//Hide "SEO Smart Links".
	remove_menu_page('sml_options');
	//Hide "SEO Smart Links → Options".
	remove_submenu_page('sml_options', 'sml_options');
	//Hide "SEO Smart Links → Custom Keywords".
	remove_submenu_page('sml_options', 'sml_custom_keywords');
	//Hide "SEO Smart Links → Import/Export".
	remove_submenu_page('sml_options', 'sml_import');
	//Hide "SEO Smart Links → About".
	remove_submenu_page('sml_options', 'sml_about');
}

add_action('admin_menu', 'plt_hide_seo_automatic_links_menus', 11);

Where do I put this code?