You can convert from video to mp3 using software that does just that go to download.com to download a video to mp3 converter - and then remove the parts you do not need using audacity or goldwave great tools audacity is free - goldwave is easy to use does a great job editing you can use it for free for at least two weeks and has free upgrades for life.
I am a DJ I use Goldwave for everything transferring files from CD voice quality it has tons of tools and is easy to use. Then save your final file either as a wav or a mp3 - mp3s are smaller in size 320 44100 will give you the best sound after converting and editing your file.