WordPress.org

1. Copy the wp-post-thumbnail folder into your 'wp-content/plugins' folder.
2. Activate the plugin through the 'Plugins' menu in WordPress. That's it.

Note: The default thumbnail is 160px by 90px which floats to the top left corner of the content of your post.

If your WordPress blog uses a theme that comes with pre-configured set of thumbnail(s) to work with this plugin, the theme's folder should contain an XML file called 'wppt.xml' created by the theme developer. In this case, it will override the default thumbnail.

For theme developers, more information on how to configure WP Post Thumbnail for your WordPress theme can be found in FAQ.