Guide on adding a new model, animation, and creature to HoMMV

Hello, please answer a simple question. I want to manipulate the models of 5 heroes in 3ds max, but I can't figure out how to load them. There seems to be a program called Arkhangel for this, but I can't understand where the models are. In data.pak, there are only .xdb and .dds files, and none of them can be opened by the program.