How to Hide iThemes Security Admin Menus

function plt_hide_better_wp_security_menus() {
	//Hide "Security".
	remove_menu_page('itsec');
	//Hide "Security → Settings".
	remove_submenu_page('itsec', 'itsec');
	//Hide "Security → Security Check".
	remove_submenu_page('itsec', 'itsec-security-check');
	//Hide "Security → Logs".
	remove_submenu_page('itsec', 'itsec-logs');
	//Hide "Security → Go Pro".
	remove_submenu_page('itsec', 'itsec-go-pro');
}

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

Where do I put this code?