I've searched youtube and can't find directions. I'm still a newbie cake decorator but I'm hoping to pull it off for my daughter's birthday in a couple months..........
Try to find a tutorial for making another kind of box, like a gift box. Those are more common kinds of cakes. Then, instead of making the fitted lid, you could put a flat lid on it like the one in this photo, which I think is a really charming toy box cake by CC member pattyasken that I had in my favorites:
Hope that's enough to get you started!