Notepad++ has a feature of its Search and Replace where you can tick a checkbox in the dialog box, to find and replace the desired string in all files in a specified directory.
I used this feature when I wanted to consolidate all my referenced attachments into one folder. Previously, I had the Obsidian attachments folder and an attachments folder for an imported group of Joplin notes. I was able to successfully consolidate all of my attachments into one folder after using the above Notepad++ feature.