How do i rip the sound of an MP4 video??HELP!?

Please can you help me out?I have an MP4 video a really love the soundtrack from,i would like to put it on an audio cd.How do i go about doing this?what is the easiest way?Will i need any special software?If so can you leave a link for me,hopefully some freeware would be great.Much,much thanks in advance for being so helpfull!cheers!