You need administrator rights to install a shared extension for all users on your network. You do not need administrator rights to install a user extension for your own use only.
* Double-click the extension file (*.oxt) in your system's file browser or choose Tools > Extension Manager and click Add.
You find complete instructions on using the Oracle Report Builder in the application help that is installed with Oracle Open Office or OpenOffice.org. Press F1 to open the Help Viewer, then enter the words "Report Builder" in the Index text box.