Choose a new image from the Media Gallery pop-up window. If you haven't uploaded the new image to the Media Gallery yet, follow the instructions in this article to do so. You can edit the image Title, Caption, Alt Text, or Description for accessibility or SEO purposes in this window. Any changes will be applied to every instance of the image edited across the site, not just the one on this page.
Click the Select button to insert the selected image. If you want to close the window without choosing an image, click the X in the top right corner.
To save your changes, scroll to the top of the Post Editor, and click the Update button.
After all changes have been saved, open or refresh the page to see the new image