Ok... I think this is how it would work...
If you wanted to change the main character to someone cool (like.. say.. Damsel ) you'd do this:
You'll need a tool called VampED, which you can get here.
Then you'll want to open and extract clandoc.txt from the pack101.vpk (and I think the VampED tool will allow you to pull out this one file)
Once you have the file, you should back it up, and then you can make the changes in notepad and then save them.
Clandoc seems to have all the file paths for the character models as well as the starting discipline info (possibly all info) for character creation.
So you could turn the female Bruja model into Damsel and then give her Thaumaturgy, Fortitude and Presence as disciplines.
NOTE: I haven't tried this yet, so I am NOT 100% sure this will work... back up your files and try at YOUR OWN RISK.
Finally a list of character models can be found here.
Edit: There's a more detailed list of character models on the site, but I can't seem to find it now. It might have been purged.