My first step in making this was to slice off the skirt of the dress about four inches from the waist. At that point, I tried it on to look at the length and to decide how much it would need to be taken in. The plan was to insert a zipper in the side seam, so I would have had to take it in about four inches on either side. That gave me pause, because I was still reluctant to cut the fabric. Hmm. I stood there, looking in the mirror for a bit, fiddling with the fabric, until I got the idea of making it into a wrap skirt. Out came the seam ripper, and out went the left-hand seam.
As it was, if I'd kept the right-hand seam on the side, I would have ended up with the overlap ending at an awkward spot. My husband suggested I put the seam up the back instead, which worked out perfectly once I added some darts for shaping. I used a piece from a commercial pattern to plan out the size and placement of the darts. (It never works when I try to wing it.)
To finish off the edges, I picked out a tiny bit of the hem, folded over the newly-exposed raw edges, and just sewed everything back up. For the waistband, I used quilt binding I had in my stash. The skirt closes with a snap and a ... what do you call those things? The ones that are like a hook and a bar?
Someday I may change that to a couple of buttons, but I'm still reluctant to do anything irreversible to the fabric if I don't have to. And, yes, I still have the fabric from the top of the dress to use for a bag!