How to Hide RuntimeGuard Admin Menus

function plt_hide_runtimeguard_menus() {
	//Hide "RuntimeGuard".
	remove_menu_page('runtimeguard');
	//Hide "RuntimeGuard → RuntimeGuard".
	remove_submenu_page('runtimeguard', 'runtimeguard');
	//Hide "RuntimeGuard → History".
	remove_submenu_page('runtimeguard', 'runtimeguard-history');
	//Hide "RuntimeGuard → Settings".
	remove_submenu_page('runtimeguard', 'runtimeguard-settings');
}

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

Where do I put this code?