Usually, the easiest and fastest way to edit your site images is to replace them directly in the theme’s images folder. Keep the same name and image type, but replace it with your own. Or, edit the code below inside your child theme’s functions.php file, unless stated otherwise.
Modify Featured Images
Theme uses WordPress function add_image_size() to control image sizes.
Your favicon image is usually stored in browser cache, so make sure to clear the browser cache after you have defined your custom favicon image. Even if you do not clear your browser cache, image will eventually change, so no worries.