Replying to final cut pro 3 help

my friend and i are doing a video and the main sound track has tons of pops and cracks in it. there is mad distortion even though it sounds fine in iTunes. I know there are all these filters and shit but what is the best way to get the song back to normal and sounding clean...

(its for the WCI so the quicker someone helps us the quicker all you people can see it that have been begging for it)

ps. if you really know whats going on, just message me...