function plt_hide_fontsampler_menus() {
//Hide "Fontsampler".
remove_menu_page('fontsampler');
//Hide "Fontsampler → All Fontsamplers".
remove_submenu_page('fontsampler', 'fontsampler');
//Hide "Fontsampler → New Fontsampler".
remove_submenu_page('fontsampler', 'fontsampler-new');
//Hide "Fontsampler → Settings".
remove_submenu_page('fontsampler', 'fontsampler-settings');
}
add_action('admin_menu', 'plt_hide_fontsampler_menus', 11);