Ripping Stunt Cars WiiWare

I'm trying to extract some models and textures from this WiiWare game called Stunt Cars, so I can convert them to a game maybe some of you might know - Re-volt.

I've already extracted the .app files from the main .wad file using a tutorial found here, and so far so good. Only thing is, the juicy files I'm looking for seem to be located deeper than I had anticipated when reading the original tut:



With that said, anyone know how to open a .epk file? I just want to extract the car models and textures, I don't care about anything else.