Currently it's only possible to import static meshes (without animations) ie, level geometry

Lstools

https://dl.dropboxusercontent.com/u/32263228/lstools.zip

Export your mesh (static) to FBX
Use LStools to convert to GR2

And then just create a model resource and a texture resource in the resource editor, then you have to create a template in the template editor that assigns model and texture.

That's all currently possible.

You can look here for hints
http://www.larian.com/forums/ubbthreads.php?ubb=showflat&Number=534502#Post534502

Though it's not a tutorial, it was just a documented test to see how this even works

Also you can find more hints as to what the current problems are here (read all ,p)

http://www.larian.com/forums/ubbthreads.php?ubb=showflat&Number=535930&page=1

Sadly there is no central location for information really, as everything is in motion....