[Alex Rodriguez]

Hi, Benterry:
I guess for your message that what you are looking for is at "Setup">"Disk Allocation".
That's where you tell your session where do you want your audio files to be recorded.
Usually when you create a new session, the audio files go to the same HD and folder where you are creating this session, but on an imported session (like yours) probably PT warned you about to check disk allocation or something like that, which you might probably had ignored.
Any way. Go to "Setup">"Disk Allocation", set it to your new HD and new allocation, and that's it. Well, that's for new recordings and processings. For the old ones, i don't know if there's an internal option for doing it in PT, I would change them manually off ProTools, like managing any other data in your Mac, move them to the Audio Files folder in your new PT session, open the session (which probably open those files correctly), but if it doesn't, it will ask you to show where they are, show it the new path (the Audio Files folder in your new sesion, where you already moved your original audio files), and just check that all your audio files are finally where you want them, by selcting "Show Full Pathnames" at your audio files list on your session, and save if everything is OK, and that's it.
Good luck,
Alex