How to take clip of downloaded movie

Probably not, as it is copy protected via DRM. You have to get that clip elsewhere (maybe it is already on YouTube), like a DVD or Blu Ray rip for example.

Yep, this is one of the classic reasons piracy exists, and will continue to.

The DRM iTunes (and other stores) use for video downloads effectively means you can't do anything with it of your own chosing under legal "fair use" requirements stipulated by law.

Help (NOT for piracy people – only for fair use situtions!):
• download uTorrent, open it and leave it open.
• type "the pirate bay mirror", find the film, click on Get This Torrent/Magnet link (ignore any Annonymous Downloads rubbish pop-ups telling you you're about to be sued by everybody, just click the Get This Torrent!).
• open that file in uTorrent. The film file(s) should eventually download.
• delete the crap "nfo" type files that come with most torrent downloads, and edit the segments in chosen app as needed.

...Then continue with your educational advancement, to hopefully get yourself future employment, to help grow the economy, unhindered by such ******** short-termist DRM nonsense, as set by some of the very companies that may want to employ you in the future. That's ironies for you.

(dupe)