I missed the little bit too, and I was going to skip over it and see how far I got because that part about unparenting the geo sounded too scary. But I went ahead and tried it. I selected all the geo parented to DEF-Body, Alt P, Clear Parent. And then I selected each of DEF-Body, Body, and Main, and changed the X of Head and Tail to zero, and then I Bone-parented the geo to DEF-Body. It wasn’t so hard or scary (assuming I did it right).