In phpMyAdmin, select your current phpBB database. Click the export tab. In the "Export" multi-select list, select all of the tables except for the user, themes and themes_name tables. Make sure the options to export both the SQL and the data are checked. Under SQL, make sure the "add drop table" option is checked. Under Data, make sure "complete inserts" is checked. Check "Save As File" and select "gzipped" for the compression. Then click Go. Save your file whem prompted to do so.
Now remove phpBB by dropping all of the existing tables and deleting all of your files, then reinstall from scratch (just follow the directions in the install file). Make sure that your table prefix remains the same durring setup.
Now, once you've got your new board up and running, go back to phpMyAdmin. Select your new DB and click the SQL table. Use the browse button to find the file you saved in the first step and click Go. Your old data should overwrite the new data.
I would HIGHLY recommend that you back up all of your files prior to this. And you may want to make a second backup of the current database (including all
of the tables this time) before you start dropping tables. Alsom if you're not familiar with FTP, find someone who is or else you may run into trouble. If your hosting provider set up the forum initially, contact them after you complete the first step and ask them to reinstall phpBB for you.
Good luck and happy turkey (or tofurkey
for us vegitarians) day.