dd the drive into a file and put said file on one of these:
https://www.overclockers.co.uk/inte...id-state-drive-ssdpedmw400g4x1-hd-069-in.html
Alternatively If the drive is small enough create a
ram drive and place it on there.
Create one or more
loopback mounts with said file.
You *may* have a slim hope of identifying the encryption method (depending on what was used) by looking at key locations in the drive image. IMO think about the owners personality. Chances are they would have used TrueCrypt with default settings? Is it Windows then clearly bitlocker (although you said linux so I doubt it).
Someone already linked to
Rainbow Tables. This is your best chance once you have an angle of attack. But you will still need to either write or download appropriate high speed decryption tests with a reliable method of detecting the decryption and hope to god it isn't a paranoid guy with more than one layer of encryption.
Good luck.