I found some long separating zippers on ebay. I plan to use three 42 inch zippers, one for the lowest layer, containing the lining and the crinoline. The second would be for the upper layer, containing, the two bottom tiers of gathered lace and tulle. The third zipper will be half used, to attach to a mini lining to zip back in under the remaining lace layer, as it becomes quite see-through without the other layers underneath.
Thus with the zippers in hand and the plan in place, and my amazingly trusting friend.... I cut the lining and crinoline out... then I basted the layers together, then cut the lace layers off (including a nice little train). What is left is this cute little lace and beaded dress!
OK, now don't panic, but I now need to reassemble the dress with zippers so that it gets back to the original condition!! I finished all the cut edges with an overlock stitch to make sure it would be stable and not fray. I then attached one half of the separating zipper to each cut edge. I used the left hip as the start and stop place, so that it would be easy to find and operate the zippers. (the bride will likely need an assistant to help her zip out, but should be able to do this without taking the gown off).
This photo is with the outer layers off, and the crinoline layer still on...
And here is the dress, with zippers attached and dress reassembled... can't see any zippers from the outside. Now it is ready for the big reveal halfway through the evening!
This was one of the most exciting alterations I have attempted. I think it is a great idea to have a dress that transforms throughout the day (she also has a matching shoulder wrap that attaches to the top of the dress for the church service part of the day)
The second is a summer dress, bright and cheerful and simple. This one is for me, and I will be making a wrap of black chiffon, nuno-felted with black and purple merino and flags of the dress fabric. Stay tuned to see the combination of these two garments. 
The third is a simple black stretch knit sleeveless wrap. It's almost done and needs a final fitting with the future owner. I have also had some wonderful comments out in the town about my coat. Strangers have asked me about the fabric and the origin of the coat. I am enjoying wearing this one of a kind coat. I have already made plans for a shorter spring jacket. 
It will look even better on my friend, than it does on my grey model! Magical.
This gives me plenty of fabric to cover the bump and plenty of extra fabric to add panels as needed. First I cut the zipper out of the back and opened the back seam of the dress and the lining. Then I cut the snug wide waistband to one inch and re-attached the skirt so that it sits right below the bodice.
On the lining I had to also cut the boning to only the length of the bodice (it went all the way down to the waist) and remount the underlining higher to match the skirt.
The short sleeve un-lined jacket is the fourth tier in the layers of hemlines. The fabric is so light it moves when she moves, and the jacket floats with the skirt.
The bodice has small tucks diagonally across, and the nature of the fabric (sheer and not-so-sheer parts) creates a natural wave to the tucks and to the hems.
Close up of the back showing the small train....
Close up view of the pearl and crystal details on the bodice....
With the tacked on draping...
Here is the first dress on the dress form.....
Now I am off to Fabricland to find a bit of trim as plan B for detailing. (instead of the sheer draping)
It is a sheer abstract floral silver-green fabric over a shiny silver satin fabric. The satin glows through the sheer bits between the leaves. The design is very simple, and I will likely find a decorative detail for the empire waist (sash, beading, decorative belt???).
The lining for all three is the same, a lovely soft ocean blue. This will shine through the sheer and make the dresses glow a bit. Hard to capture on camera. 
