Unlinking Image Pages On My Whole Site

I really don’t like that my images link to a page including only the image, rather than to the image directly. I had no idea how to fix it, but it seems that I can do so by changing “file url” rather than “attachment post url” in the future.

However, I now have over 300 images that are linked incorrectly. Is there any way to fix this without going through my images one by one and changing the links? That would take hours.