Converting a GST 7.7 to brushless. Help?

Bah, been going over the gears over and over, but I can't figure out exactly how to do this. The gear that's directly on the other side of the pinions reaches down to the center diff, and if that gear was stuck to the pole I could simply remove all the others. But it isn't stuck.

The centrifugal clutch gear isn't attached to the "pole" either, and I cannot screw it or attach it to the gear next to it.