Who owns the iLok? Even if its not yours, you can still install the iLok manager software and open/view the licenses on the iLok. I'm still getting the feeling that there is a lot of info we don't know(making it hard to help)
Shooting in the dark; you can sell an iLok and licenses in a few ways.
1-hand it to the buyer and give them the account and login info(and they keep using it as you)
2-Transfer the licenses to the buyer's iLok account(which involves a fee), the unregister the iLok and hand it to the buyer(who can then register it to their iLok account.
If you are the registered owner of the 003 and Pro tools software, you can do a Transfer of Ownership form, which would then give the buyer access to Pro Tools downloads(for whatever reason, Avid makes it tough to access software downloads to anyone that isn't a registered owner of the software).