Hi Mandy,
To upgrade your Little Reader (I assume you originally installed it using a CD), please go to your BrillKids Account's "My Purchases > Little Reader Software" page. There is no button labeled "upgrade" there, but what you need to click on is the "download" button, and this will give you the installer for the latest version of Little Reader.
You may refer to this article for detailed instructions on how to get LR from your account:
http://support.brillkids.com/entries/20370881-installing-and-setting-up-your-little-reader-from-your-brillkids-accountI hope this helps! If you are having problems with any of the steps, just write to us again.