I think it's towards the bottom of
this page, specifically, the following image:
So, all you need is the little adaptor on the output shaft. And you can remove the extra top gear for a little weight savings. However, you will need a spacer in place of the removed first gear. Either keep that gear in there, or cut the gear away until just the hub remains. Some people use stacked bearings, but a modded gear is cheaper (since you're removing it anyway) and lighter...