Is there some software that works good (free) to remove audio from a MP4 video file?

Edit: This would be used on a Mac.

I found others have said IMovie works well, but I have no clue how to use it. Anyone else tried it?

ffmpeg will do the job. How comfortable are you with your Mac's command line interface?

Not at all lol. I'm still trying to get used to this. I figured out that IMovie thing works well. You can just mute the audio after you import the video. There is some movie maker thing that Sony has that will link the video files together to make it 1 file.

I wished I knew more about the mac, but for now it's just baby steps I guess.

I have used any video converter in the past and its free. Its pretty easy to use. Just watch the install and do custom to make sure your not installing anything else.http://www.any-video-converter.com/products/for_video_free/