PS2 Audio Switching

[Forever Strife]

Ok. here's the deal, recently a PS2 RPG by name of Radiata Stories has been released in the US, I despise, the dub, there's an option to use just subtitles and no voice audio, but it makes the game boring, because there are may parts where there is no sound/background music, and then + no voices.

So, I also have the JPN version of this game, I want to remove the Japanese voice audio and put it in the USA version of the game. SO the ultimate goal is Japenese voice audio with english subtitles. I've been told something similar to this has been done with a game called Winning Eleven. However, I have no idea how to do this, anyone to know how I should go about doing this? PS2 is modded btw.