Well I don't think you can uninstall it, but basically if you just set the preloader to disable and delete the hacks.ini on your sd. It would be just the same as uninstalled.
It's ok, I managed to uninstall it. I ripped the 3.2E SysMenu and used a WAD installer to reinstall. And to my research, AnyTitle Deleter would brick the Wii. Since Preloader just renames the SysMenu and puts it's own .DOL in it's place, the Wii wouldn't find a .DOL on Boot, so it won't boot.But this app is a good idea (Just like BootMii...), the only thing it lacks is an easy uninstallation.