Confused on mob model creation

I want to add a mob to the game with a custom model. I tried to use Techne but pressing the button to install and run it does nothing. Blender is just confusing and I have no idea of any other external programs for the creation of .java models. I also have no idea on how to use custom models in the skin editors to create the visuals, but that is more easily solved. Can anyone help me out with this strange problem? In the meantime, I will probably use a placeholder model and texture like the pig model.