OK, so I have finally pulled together a complete page on making koji for sake brewing along with the videos. As with the videos for brewing sake there is nothing amazing here but that may, in fact, be the amazing thing. When it comes to making koji, like brewing sake, it is all very doable.
I believe the text for the koji making page is very readable and stands on its own without the videos. However, the videos may help to solidify what is said in the text. All in all I hope you find the page useful and enlightening!
Oh, FYI, I have linked the koji making page into the top of the Recipe page for convenience.