[Pharo-project] How to update Pharo

In the document at: http://code.google.com/p/pharo/wiki/HowToContribute, I find - Download the latest Pharo image from http://code.google.com/p/pharo/wiki/Downloads?tm=2. - Launch the fresh image and load the latest updates by using the option in the menu. The Pharo-1.1 One-Click image has no "update" option in the menu. Should I be using a different image? How would I go about updating the One-Click image "manually"? Regards, TF