The zipper tape is still held to the case by one thread

Cut it and work your way around the case, the same way as for the first fabric, to undo the seam

On the inside there are 2 seams: one that holds the tape to the leather, and one that holds the outer fabric (the sort of "back pocket" of the case) to the leather. To avoid mistakes, undo the seam from the exterior of the case (orange stitches)