Now that your zipper is in place, you can sew the seam from the bottom of the zipper (where you sewed to, even if there is more zipper hanging off) to the bottom of the skirt. There will be a little gap between the bottom of your zipper sewing and the start of your new seam, but don't worry, we'll fix that by hand. Press the seam open.
Next, you'll want to sew the side seam in the lining. Pin the entire lining side. Then, mark where your zipper ends. Baste above that mark (sew using a long stitch that is easy to remove). Sew the bottom of the skirt with a regular length stitch. Press the seam open. Now, using your seam ripper, remove your basting. Basting before pressing helps guarantee your pressed opening is centered with a 5/8" "seam."
|Here, I have just sewn the entire lining side seam.|
I don't know if you can tell from the picture, but the
above the zipper is basted, and below is sewn regularly.
|Pressed open the seam|
Now, stitch down your pressed edges that you just created by removing the basting stitches.