WordPress – update your own blog platform.
To see WordPress in action on this website, click here.
As of WordPress 2.7.x, there already exists a feature to automatically upgrade to the latest version of WordPress.
Prior versions to that required a separate plug-in, so this lesson is a bit out-dated – what you need to do is download the latest version of WordPress and overwrite your current version. See Lesson 7 for how to download, extract and install WordPress.