My father in law has a Time Capsule connected to his network. He previously had an open network, but encrypted it last night, without thinking about what that would do to the Time Capsule. Now, of course, the Time Capsule doesn't know the network key. How do you change that? He tried going to Airport Utility, but it couldn't find the Time Capsule (I assume because the network's encrypted now, and the Time Capsule doesn't know that).