How to Hide CP Contact Form with PayPal Admin Menus

function plt_hide_cp_contact_form_with_paypal_menus() {
	//Hide "Settings → CP Contact Form with PayPal".
	remove_submenu_page('options-general.php', 'cp_contact_form_paypal.php');

	//Hide "CP Contact Form with PayPal".
	remove_menu_page('cp_contact_form_paypal.php');
	//Hide "CP Contact Form with PayPal → Manage Forms".
	remove_submenu_page('cp_contact_form_paypal.php', 'cp_contact_form_paypal.php');
	//Hide "CP Contact Form with PayPal → Add ons".
	remove_submenu_page('cp_contact_form_paypal.php', 'cp_contact_form_addons');
	//Hide "CP Contact Form with PayPal → Help: Online demo".
	remove_submenu_page('cp_contact_form_paypal.php', 'cp_contact_form_paypal_demo');
	//Hide "CP Contact Form with PayPal → Help: Documentation".
	remove_submenu_page('cp_contact_form_paypal.php', 'cp_contact_form_paypal_doc');
	//Hide "CP Contact Form with PayPal → Upgrade".
	remove_submenu_page('cp_contact_form_paypal.php', 'cp_contact_form_paypal_upgrade');
}

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

Where do I put this code?