With this pluginyou can face two goals:
· File Replace Sometimes you have an image used in several spots (slider, gallery, feature image, …) and if you remove it and upload it again, as it gets a new ID, you will need to select the new one all around but you could forget a place. To avoid it, use this plugin.
· File Rename Sometimes we upload a file as it comes from the mobile camera and later we realize that the file doesn´t have a ver SEO-Friendly name. Here you can rename the file.
None of both functionalities will breake any link where the image is pointed by its ID but this action doesn´t do a Search and Replace along the post entries.