I should mention too that if he WAS going to use Creo, I think Ryan's method is the better one.
Doing a file backup will only bring along files currently in session and required by the item being backed up. It won't bring drawings (assuming the assembly is open), it won't bring any suppressed components, it won't bring copy geometry references, etc.
Also, to disconnect from Windchill is as simple as double clicking on "No Server" in the server manager window. You certainly don't have to shut down and fire back up with a different cache location just to work on stuff outside of Windchill.
My 2 cents worth. 🙂
Tom U.