If you're using a 22-inch zipper, this part is a lot simpler. You just keep on attaching the zip down the side seam, and the pocket is all attached to the front. Close up the pocket, and continue the seam as you normally do with an invisible zipper. If you're using a 12-inch zipper, your zipper stops in the middle of the pocket. So you have to attach the rest of the back pocket piece to the back. I did this in two steps. First I used my regular zipper foot to get as close as I could along the bottom of the zipper (just as you would close the seam when attaching an invisible zip the normal way).