Hi Mikki,
The following is just my limited knowledge of the JB7. I have two of them now and have done some work on them such as replacing the CD drives and changing the HDDs. But there is no trechnical information available for this model anywhere that I can find.
Regarding upgrading the 480GB HDD with a 2TB SSD, I don't think that will work, as I believe that there is an overall limit of somewhere around 500GB for both HDD & SDD units within the JB7. The other problem is that the 'Disk Format' function is not available, so even if you install the SSD, you cannot format it. AudioTech does provide preformatted 480/500GB SSD/HDDs but I haven't seen anything larger than those.
You could contact AudioTech and ask them for advice as I could be wrong about that upper limit.
I have found a way of cloning HDDs by doing an exact sector level copy from one disk to another using a PC to do the copy, but than only works for copying to another disk of the same capacity.
Regards,
Peter.