You can’t migrate BFD1/BFD2 serials. You have to get replacement serials and input them into the LM to add them to your BFD Drums/inMusic account.
These are equivalent libraries, but you can’t use the original BFD1+2 content with this BFD3 version. Once you get your new serials, add them to the LM, you can download and install those new libraries. Then, rescan your content locations in BFD3.