How to Hide SRS Simple hits Counter Admin Menus

function plt_hide_srs_simple_hits_counter_menus() {
	//Hide the "Simple Counter" menu.
	remove_menu_page('srs-simple-hits-counter');
	//Hide the "Simple Counter → Dashboard" menu.
	remove_submenu_page('srs-simple-hits-counter', 'srs-simple-hits-counter');
	//Hide the "Simple Counter → Settings" menu.
	remove_submenu_page('srs-simple-hits-counter', 'srs-simple-hits-counter-settings');
}

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

Where do I put this code?