Hello, don't be worried about reformating, you can see them with a tool NTFS for Mac. Because Mac can't write NTFS file system but Windows can, it's not compatible with macOS. With iBoysoft NTFS for Mac, a powerful tool, you can delete, edit, rename, and write files on your external drive without formatting.
Free download it~ And you can see it and edit your files seamlessly on both your Mac and PC.