The easy thing to try is;
(you probably have an older version of iTunes, so it's probably under a seperate tab)
iTunes -> Preferences -> Import Settings -> Select Higher Quality (192k) and then Mp3.
Once you do that, you can convert any song you click on in your library to mp3.
However, i think if it's DRM'd still, this won't work.
The only true way to get around a DRM is to burn the songs to a CD (not a data disk, but like, written to a CD so it could go in a standard old fashioned cd-player) and then import the songs from the CD.