Changing MU's Voice FIles

[TuffinMuffin]

So to include only the key details, I want to swap an English Avatar voice bank with a Japanese voice bank (Boku #2, the voice option that was excluded from the english release's japanese voices), i'm assuming this can't be done through simple save editing, and i'm not 100% sure about the process, will any of the sound files themselves need modifying to work correctly? Or can I just replace the English MU files with the Japanese MU Files and everything will work fine?

However, if this isn't an option, is it possible to force the Boku #2 voice to play in the English release with a hex edit? Or do the unselectable voices not exist in the English release all together?