Changing the AI Orc .dts

Hi,

I'm just begining with the engine and I would like to do a simple task but I don't know where to begin...

I have a .dts and I would like to replace the orc ennemy by my own shape... I thougt about changing the script player.cs and replace the .dts name by mine but this will also change the player...

So my question is how to change enemy .dts without changing the player .dts?

Thanks for answering.