I think you might be better off asking the question in the M2TW section. You definitely can't just do it with text editing and adding the models/textures as you would between RTW and BI mods. The models and textures are both different. Textures I'm sure can be converted, look for Alpaca's texture/dds converter for that. The models might be more of a problem, though I think the guys who worked out how to mod the M2 mesh files might have developed something to help export from one format to another.

As I said look / ask in M2 section if you haven't already.