I am deep in the middle of this.  My cat chewed thru 3x2Tb external drive power adapters , 4 USB cables, my home phone line, and my speaker cables over the weekend.  Once I started taking things apart I decided to just spend the next days getting it all right.  First I have downloaded and bought the partition software.  Then I cloned the dual boot system drive to a 1tb MyBook.  WhiLe that was going on (7 hours),  I drove over to MicroCenter and got a 2TB extreme barracuda internal, and a USB 3.0 drive enclosure.  I'm in the middle of cloning the system drive again to the new 2tb drive.  Then I plan to try to just swap it for the system drive and see what happens.  Meanwhile, the cat is in timeout.