Covert a .mp4 movie's audio alone to mp3 without changing the video quality

[ckarvnd]

I have a dvd rip of an English Movie in .mp4 format.The total file size is 699 MB.The audio is encoded using AAC codec
I have an external media player which accepts .mp4 format with only mp3 support.When I use the above file,my player is showing unsupported file format.Is there any video conversion software(freeware/paid version) which will help me in retaining the video format .mp4 and convert the audio alone into .mp3 format with correct synchronization

[Baldrick]

Try xmedia recode, open mp4. Under format choose mp4, under video choose copy mode(no reconversion), under audio choose mp3 audio. Add job. Convert.