Welcome to the Break Up The Concrete Challenge. First check out the intro from The Pretenders who will tell you what to do and what you will get if you win!
All you need to do is download the GarageBand project which provides the entire song in mult-track format. (GarageBand is included free on every new Mac). Once downloaded you can easily use loops and instruments built into GarageBand to remix the song. Once complete you can export your remix as an MP3 file and upload using the form below.
For more information on GarageBand and tutorials to help get you started head to.... www.apple.com/garageband
Requires GarageBand 3 or greater. Mac OS X Tiger 10.4 or higher. 512 megabytes of RAM. (1 Gig recommended)