Endnote 7.5 reinstallation - / product key lost /

We want to change the harddrive in a Macbook. The Macbook with EndNote6 was a gift from the University some years ago, so we don`t have the product key. Only the number that is shown when I go to „about“ and the name of the University. Is there a chance to get the endnote running again after install it new? Is it a option to use migration and there is no key needed?

Thanks a lot,

Christian