How to Hide Projects Custom Post Type by mbaierl Admin Menus

function plt_hide_mbaierl_projects_cpt_menus() {
	//Hide "Projects".
	remove_menu_page('edit.php?post_type=project');
	//Hide "Projects → All Projects".
	remove_submenu_page('edit.php?post_type=project', 'edit.php?post_type=project');
	//Hide "Projects → Add New".
	remove_submenu_page('edit.php?post_type=project', 'post-new.php?post_type=project');
	//Hide "Projects → Categories".
	remove_submenu_page('edit.php?post_type=project', 'edit-tags.php?taxonomy=project_category&post_type=project');
	//Hide "Projects → Tags".
	remove_submenu_page('edit.php?post_type=project', 'edit-tags.php?taxonomy=project_tag&post_type=project');
}

add_action('admin_menu', 'plt_hide_mbaierl_projects_cpt_menus', 15);

Where do I put this code?