it's not going to be easy and the quality will be pretty horrible. But
if you really want to do it, download the youtube video to your
computer using a youtube downloading site like
http://video.qooqle.jp/dl/. It'll be downloaded to your comp as a flash
file. Then you'll have to download a flash to avi converter (or flash
to mpeg or something). Once your file is converted to an avi or mpeg or
mov, just import it into your editing software and cut it up!