Use a file converter app or website
Upload the MP4 file
Select MP3 as the output format
Start the conversion
Download the converted MP3 file
Use VLC Media Player
Open VLC
Go to Media
Select Convert/Save
Add the MP4 file
Choose Convert
Select MP3 as the profile
Start the conversion
Save the MP3 file
Use Audacity
Open Audacity
Import the MP4 file
Export the audio as MP3
Save the file
Use FFmpeg
Open a terminal or command prompt
Run the command ffmpeg -i input.mp4 output.mp3
Wait for the conversion to finish
Use online tools
Search for an MP4 to MP3 converter
Upload the MP4 file
Convert it to MP3
Download the MP3 file