Does anyone know? (random q)

I have a gorgeous skirt that I love but is now a few sizes too big. I has a fish tail type thing at the back (is that even what it is called or does that make no sense at all!?)

Would it be ridiculously hard to make smaller? I woulod have to take it to a professional but I am wondering if it is even worth the effort?

You can take clothes in by up to 2 dress sizes without altering the shape and style of the garment.

Yeah, I imagine they wouldn't even have to touch the fish tail, just take in the seams at the sides (unless of course, there's no side seams!).