You
don't "extract" the movie from the mpq simply because it's not an MPQ!
The following MPQ aren't MPQ at all:
HumanEd.mpq
HumanOp.mpq
NightElfEd.mpq
OrcEd.mpq
TutorialIn.mpq
TutorialOp.mpq
UndeadEd.mpq
These files are just renamed DivX AVI using the DivX (TM) Decoder Filter v5.0.2.0 (Copyright © DivXNetworks, 2001).
This codec is stored in the file "blizzard.ax" (in the war3 drectory).
To play the movies, install DivX codecs 5 and just open them with the media player. You don't even need to change their extension but you can if it makes you feel better.
In case you don't get it, rename for example "HumanEd.mpq" to "HumanEd.avi".
You need the DivX 5 codecs. If you really want to convert these to mpeg2 (DVD), in my opinion it's a wast of time.
Anyway, try the sites like
http://www.doom9.org