Easy way to dual class into specialist

I found a way to dual class into a specialist class. Start a human character in your specialist class. Make your first save game. Next go into your game editor e.g. eekeeper and edit the save game.
Under characteristics change them to your first preferred class, e.g fighter but leave the specialty alone.
Advance for a while in your first class and when you want to dual, you will receive all the special bonuses of the kit without having to do anymore editing.

Can't get it to work for mage specialists.