Differential disassembly / combine

Hello Subaru Freaks! I’m currently converting my SVX to manual transmissions. Since the translation of the rear diffs has to be changed from automatic to manual transmissions, I wanted to ask you if you could do it yourself? So I would combine the diffs from the Legacy with those from the SVX, because the lateral drive shafts are different in the Legacy. With the SVX they are plugged into the diff., with the Legacy looks out a gearing. Now my questions: someone already has a D What do you have to pay special attention to? what would be easier: inserting drive ends from SVX Diff. into Legacy Diff., or inserting plate wheel from Legacy into SVX Diff.? does anyone know a company in D that specializes in differential work? Thank you in advance!