How to Replace images in a Post or Page
Replacing an image is like deleting the current image and replacing it with a new one. Click Add Media Button then you will have options either to Upload an image from your computer or you could choose an image from a Media Library.
To replace an image in a post or page, select the image you want to change and click the remove icon. Next go to media and either upload a new image or select want currently in your media library. Adjust the images settings and click “Insert into Post”, the image will be place exactly with the original was.