Transporting RTW units to BI

I'm trying to get some RTW models and skins etc. to BI. I'm trying to add the Gauls Warband unit to the Alemanni. What exactly do I need to do? So far I've:

1. copied the warbands text from RTW descr_model_battle to BI descr_model_battle. I also added that line just below the name that all the BI models seem to have
2. copy the Gallic skin and sprites in photoshop and rename it for the Alemanni. What should I name the folder for my BI skins?
3. add the name of the skin and sprites to descr_model_battle
4. add the unit to export_descr_unit and export_descr_unit enums

Any help would be greatly appreciated.