My band just finished recording our first original song off a 4-track Tascam, and I was just emailed an MP3 he extracted from the cassette. I now want to touch it up: The snare drum is too loud, and there are points I think the distorted guitar could be tuned down.

Does anyone know any software (perferably free) that can adjust select frequency ranges from a track to turn down / remove?

All suggestions are appreciated. I'm sure this one has an easy solution...

The MP3s are located here, the problem song is "Super Girl': http://www.ogghelp.com/dsmith/strategery/