You can change your starting abilities on the race setup screen. If you mean actually modifying the inherent bonuses each race gets then you can edit the values in the the race xml files in your My Documents\My Games\GC2TwilightArnor folder. You can also go to the folder where you installed the game and look in the data folder. I think the file is raceconfig.xml but am not sure. If you modify the last folder you should back it up before you do so. Any changes outside of the game will trigger a cheat flag in the Metaverse.