[Need Help] Just upgraded my hard drive to 2TB but cannot restore backup data from hard drive.

I was on the beta firmware before I upgraded my hard drive. When I upgraded the HDD, I installed firmware 4.74. Now I cannot switch to the beta firmware and when I try to restore my backup data, it says that I need to upgrade my firmware before I can restore the data... The only way to fix this that I can think of is to find a copy of the 4.73 firmware or the beta firmware, but I can't find those anywhere... Any ideas?