I have never made a pattern of hers, and I don't understand the directions in number 6, but I think I do understand the directions in number 7. It is telling you to sew the perimeter fabric to the Death Star in two sections, separately: the top half and the bottom half. Then you stitch the two halves of perimeter fabric together, followed by stitching the two halves of the Death Star together.
I'm unsure, but it sounds to me, in the number 6 directions, that you are sewing together a circular piece and a concave framing piece, the way you inset a circle. And it seems to me that you are doing it with either a half inch seam allowance on both pieces, or a half inch seam allowance on only the concave framing piece, while using a quarter inch seam allowance on the circular piece (which seems like it would be hard to do imho).