function plt_hide_caxton_menus() {
//Hide the "Caxton" menu.
remove_menu_page('caxton');
//Hide the "Caxton → Caxton" menu.
remove_submenu_page('caxton', 'caxton');
//Hide the "Caxton → Contact Us" menu.
remove_submenu_page('caxton', 'caxton-contact');
}
add_action('admin_menu', 'plt_hide_caxton_menus', 1000000000);