Smaller button-down shirt?

How would I go making

into a shirt like

I have seen no posts, tutorials, or anything else for something like this.

All I keep running into are t-shirt posts.. is this unheard of?
Basically I want to give it that "split" dress/duster style and much more fitted.. what you see when its pinned back..
Any advice at all? it has 4 darts, 2 in front, 2 in back. its a large-sized medium (women's) and I would like it to fit around x-small.
where it is fitted, its a little less than 28".
Should I remove the darts?
Is there no non-tedious way to go about doing this?
I also kind of want to make it off the shoulder, with thick straps on the shoulders, will that be too hard also?

I could leave it pinned, but I want a less-obvious way to make it smaller. plus pinned back it gets all bunchy, because there is ALOT of excess fabric.
If there's a no-sew way to just hold it all back, that would be fine, but if I have to cut and sew and measure and glue or whatever, that's fine too.
I've thought about a lace-up back, replacing the back with less, new fabric, removing the darts and reshaping it.. but I really have no idea how to go about doing it at all.

by the way, the second picture of the shirt is it

Sorry for all the questions, and..
Thank you thank you thank you for any advice!!

Haha, please excuse my bra showing through, and my messymessy room.
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