How to Hide Bulletin Announcements Admin Menus

function plt_hide_bulletin_announcements_menus() {
	//Hide "Bulletin".
	remove_menu_page('bulletinwp-options');
	//Hide "Bulletin → Bulletins".
	remove_submenu_page('bulletinwp-options', 'bulletinwp-options');
	//Hide "Bulletin → Add New".
	remove_submenu_page('bulletinwp-options', 'bulletinwp-options-add-new');
	//Hide "Bulletin → Settings".
	remove_submenu_page('bulletinwp-options', 'bulletinwp-options-settings');
	//Hide "Bulletin → Contact Us".
	remove_submenu_page('bulletinwp-options', 'bulletinwp-options-contact');
	//Hide "Bulletin → Upgrade".
	remove_submenu_page('bulletinwp-options', 'bulletinwp-options-pricing');
}

add_action('admin_menu', 'plt_hide_bulletin_announcements_menus', 1000000000);
Where do I put this code?