You can take the key off after the system has started, but it must be replaced before midnight or your coach will turn back into a pumpkin, Cinderella. (System will try to revert to demo mode, which can cause all sorts of things to stop working.)
You should be able to do the upgrade by "borrowing" the dongle, but keep in mind that the Unity version is a keyed feature, and the version stamp on the dongle needs to match the version of the system it's attached to.
You could also use the 'keyless' demo mode if you just want to practice the upgrade procedure.
Scott Morgan
Cisco Systems TAC
