How do you change Japanese shows to English?

To switch the audio track in a video file, the video file must already contain both audio tracks. If you are sure of this, then you need a player that supports such features. The easiest way to get support for most containers and encodings is through VLC (videolan.org/vlc) or CCCP (cccp-project.net). CCCP will use Media Player Classic Home Cinema as a video player and VLC is it's own standalone player with built in codec libraries. To switch the audio track, you first open the video with either player and right click anywhere where the video is playing. The context menu should contain an "Audio" menu where you can switch between the different audio tracks in the file.