This video will give you a quick demonstration of how to modify the Contextual Help tab on any WordPress admin page. This trick is particularly useful for users wishing to add extra information to an already-existing help tab, such as the one on the Themes or Plugins page.
This tutorial is an extension of the quick tip on adding Contextual Help Tabs to your plugin.
To assist you, here is the code used in the video.
Note: this works differently in WordPress 3.3