I've been testing upgrade of OEPE from one version to another.
Upgrade might not be as intuitive as for other applications that could be as easy as one-click.
To get the latest/greatest you need to add an upgrade site under Help > Install New Software > Add.
For Galileo builds (which is the latest/greatest that we support) people should use this URL:
http://download.oracle.com/otn_software/oepe/galileo/
Then you can use the Check for Upgrades choice.
One thing that some people might need to do is update their proxy settings under Window > Preferences > General > Network Connections. If I'm behind a firewire I choose Manual and then the URL and port