From the fireboard wiki:
1. First, unpack the archive on your local computer. First, unpack the archive on your local computer.
2. Go to your Joomla! Administration > Installer > Componenets
3. Select the “component_Fireboard_Forum_1.0.4.zip” package and click on “Install”.
4. After a successful installation, go to Components > Fireboard Forum
5. Once you enter the control panel, at top of the page you will notice a dialogue is asking you weather you want to upgrade from “Joomlaboard” or a “Clean Install”. Click on “Import from Joomlaboard” and Fireboard will automatically import your database and file structure.
If you have any further questions or problems, please visit the BestofJoomla.com forums.
Note Fireboard does not modify your Joomlaboard installation and database. Feel free to try Fireboard while your Joomlaboard is still running on your website.
www.bestofjoomla.net/wiki/com_kunena/rel.../upgrading?s=upgrade