function plt_hide_planaday_api_menus() {
//Hide "Planaday".
remove_menu_page('planaday-api');
//Hide "Planaday → Welkom".
remove_submenu_page('planaday-api', 'planaday-api');
//Hide "Planaday → Instellingen".
remove_submenu_page('planaday-api', 'planaday-api-general');
//Hide "Planaday → CSS".
remove_submenu_page('planaday-api', 'planaday-api-css');
}
add_action('admin_menu', 'plt_hide_planaday_api_menus', 11);