How to Hide Libsyn Publisher Hub Admin Menus

function plt_hide_libsyn_podcasting_menus() {
	//Hide "Libsyn Publisher Hub".
	remove_menu_page('LibsynSettings');
	//Hide "Libsyn Publisher Hub → Settings".
	remove_submenu_page('LibsynSettings', 'LibsynSettings');
	//Hide "Libsyn Publisher Hub → Content".
	remove_submenu_page('LibsynSettings', 'LibsynContent');
	//Hide "Libsyn Publisher Hub → Import Feed".
	remove_submenu_page('LibsynSettings', 'LibsynImports');
	//Hide "Libsyn Publisher Hub → Debug".
	remove_submenu_page('LibsynSettings', 'LibsynDebugLog');
}

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

Where do I put this code?