how to convert mpeg4 to mp3

[skinnyfries]

I need to post my song on this website, but it won't except mpeg4 files from itunes.. so how can i convert it.. and if you a program or something can you give me step by step instructions?

[fo3nix]

use this:
http://www.dbpoweramp.com/dmc.htm

together with this:
thishttp://www.dbpoweramp.com/codec-central-mp4.htm

[SpyWriter]

I have tried this as I want to extract parts of songs from iTunes to use as ringtones using Audacity. Seems to work on various formats but not mpeg4