You may have noticed that some torrents come with multiple audio files. Since a lot of devices can only read one audio track per mp4, I made this tutorial for you to be able to swap the audio to that of another language. Obviously, this would need to be done prior to splitting <4GB if needed.
Start off by downloading Yamb: YAMB » Yet Another MP4Box UI
– Download & run YAMB from the link provided.
– Select first visible option
– Add original video and new audio
– Deselect old audio
– Rename & click next