WordPress by default is tightly integrated with Gravatar.com.
To replace the default avatar sets takes lot of hard coding on the developer's part, for such an usually unseen site detail.
This is why using a WordPress plugin like WP User Avatar has its advantages.
It allows the webmaster to install it, and just select one of the images from his Media Library as the site's new default avatar. That's it, no hard-coding the WordPress core or messing around with the FTP to replace images.
Additionally, WP User Avatar provides a way for users to customize their profile picture and a TinyMCe button for WP's WYSIWYG editor that redactors can use to embed an user's avatar inside a post or page via a shortcode.
Unpack and upload it to the /wp-content/plugins/ directory.
Activate the plugin through the 'Plugins' menu in WordPress.
· WordPress 3.1 or higher
What's New in This Release: [ read full changelog ]
· Ability to disable Gravatar avatars.
· Upload size limiter for Contributors & Subscribers.
· French, German, and Spanish translations.