Unixmen shows you how to upgrade CentOS 5.6 to CentOS 6.0

If you only have been using CentOS for a while, you might already be aware of how to upgrade to the latest release using the yum update command. However what you may be unaware of is that the yum update command can only be used for upgrading to the latest minor release. Generally this is because a major release will contain major security fixes, kernel updates and new applications.

  Upgrading from CentOS 5.6 to CentOS 6.0