How to size down these milkmaid-style cups

Hi everybody!! Beginner sewist here :) I thrifted this floral dress that was about 2 sizes too big for me. I've already sized down the waist and it fits me perfectly. The only thing I can't figure out how to do is size down the bust cup area.

I have a small chest, and you can see (especially from the side profile) that there is a lot of excess fabric. I have no idea how to make these smaller so any advice would be greatly appreciated!!

I also included a photo of the dress inside out in case that helps.

A few inches of excess fabric around the bust

Front view

Inside out view

Close up of front

https://preview.redd.it/gwp2rtb9bzxg1.png?width=1134&format=png&auto=webp&s=52e92e7de04b3267268ffd70e77ad96ccd4839e6