Use the Media Manager and the COPY option.
Or....just manually drag it from the desktop to the external...It'll copy it too. Then trash the ones from your iMac (wait to empty the trash). Then RECONNECT when you go back into FCP. Once everything has reconnected...THEN Empty your trash.
Shane
GETTING ORGANIZED WITH FINAL CUT PRO DVD...don't miss it.
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Little Frog in High Def