Installing extensions is pretty easy. Download the extension.
Then in OpenOffice.org, choose Tools > Extension Manager.
Select My Extensions and click Add.
Find the extension file you downloaded.
An installation process runs, and you’ll see Enabled next
to the extension. For some extensions, you’ll need to restart OpenOffice.org.
To use it, look for
a new menu, new menu items, new toolbars, or all three. Often there's a toolbar or menu called Add-On.