First, I apologize if this is in the wrong forum or otherwise breaks normal MMOwned conventions. I tried to post in the general model edit forum and can't because of my pitiful post count. (i don't like posting unless i have something to say lol)
That said, this is my first attempt at model changing, and major credits to reflex0rzor for his step-by-step guide.
Code:
Drop worgen.MPQ into your Data folder. Rename it to patch-4.MPQ or similar, and remember to remove
or rename any other Draenei Female -> whatever MPQ files you may have to avoid problems.
Your final file path should be something like C:Program FilesWorld of WarcraftDatapatch-4.MPQ
Note: caps on MPQ is generally important.
Your worgen will probably look texture-less in the character screen. Just log in, it is fine in-game.
-reg
Sample Image:

Download links:
Main: http://myhostedfiles.org/edit/DraeFemtoWorgen.rar
Mirror 1: DraeFemtoWorgen.rar - FileFront.com
Mirror 2: MEGAUPLOAD - The leading online storage and file delivery service
I may do further draenei female edits in the future. This is just something I wanted to do after an alt karazhan run (torment of the worgen book) gave me motivation.