You start with the center portion of the panel. Insert the wire in the sleeve, and use a hog ring pliers to attach the center front to the wire, through the foam at the bottom of the slot. Work back and forth on the front, to assure you have the covering centered. Then do the sides. I've done a lot of these, and sometimes I miss the wire, cut the ring, and do it again. The factory service manual shows correct placement of the wires.
Once the center panel is done, roll the bolster panels over the frame. I do the front first, then press the seat against the floor and roll the rear corners over.
As before, start at the center-front. Take your time, working out wrinkles as you go.