Oh, you mean how to disable existing Guest accounts? I don't know if a Profile will do that without a full reboot taking place after the profile is pushed. Can't say as I haven't tested that to be honest. Are these guest accounts currently being used? As in, users are logged into them? Or are you more looking to ensure they won't be usable down the line? I don't know for sure, but my expectation would be that, once the profile is applied and the Mac reboots (or perhaps not even necessary) next time someone tries to log in as Guest, it won't allow it. Thats my expectation anyway, but again, I don't know if that's actually how it would work in this case.