I'm not experienced in video editing, but anyway, here's how it
can go.
1. DL the FLV file liao convert it to AVI for editing.
2. Clip the portion you want in a video editing application
(Windows Movie Maker should be sufficient) and export it as another
AVI.
3. Import the clip into Flash and export it as an animated
GIF.
(Step 2 can be done in Flash if the AVI file from Step 1 is small,
approx
If you find the quality of the animated GIF is not up to your
expectations, and you are willing to spend a little more time,
here's a thread that you may want to refer to.
http://www.ozzu.com/ftopic74008.html