<dropping...>
Easy, but tedious - especially if you have an ancient, creaking machine <wizard> to work with. It takes me five minutes just to load 3DS :-P
Each model for each race and pheno-type would need to be copied, renamed and mirrored. Add other genders, if you want to really support diversity ;-)
I've got too many irons in the fire to jump on this, though. <oooh! we torturing someone tonight, boss?> Oh, hush.
<...a couple coppers>