I've got Google Drive installed on Mac OSX 10.8.4 -- I no longer work and company X and want to associate Google Drive with company Y account. 

I no longer have access to the old account so I can't go through the normal process of signing in and deactivating the account. I have tried deleting and uninstalling and still am being asked to sign in as the old user.

What did I miss? Where does Google Drive store the association with the old account?