1. Install the base package in the Salesforce organization that you plan to use to upload theextension.
2. Build your extension components.Note To build an extension, installthe base package and include a dependency to that base package inyour package. The extension attribute will automatically become active.
3. Create a new package and add your extension components. Salesforce automatically includes somerelated components.
4. Upload the new package that contains the extension components.
5. Proceed with the publishing process as usual. For informationon creating a test drive or registering and publishing your app, goto http://sites.force.com/appexchange/publisherHome.