FIRST BACKUP YOUR CURRENT PHPBB INSTALLATION & DATABASE
If you have installed phpbb via fantastico:1. Log into your control panel.
2. Double click the fantastico icon.
3. Click on phpbb you should see an update option.
That will update phpbb for you.
Otherwise manually update your phpbb installation:Download the Changed files:
http://kent.dl.sourceforge.net/sourceforge/phpbb/phpBB-2.0.11-files.zipOpen the zip file, you will see files called 2.0.x_to_2.0.x.zip
If you are upgrading from phpbb 2.0.8 look for the file called:
2.0.8_to_2.0.11.zip
Extract these files into a folder on your local computer. Then upload
all files overwriting your current phpbb files.
WARINING: You will need to reapply any hacks, modifications.In the main phpBB-2.0.11-files.zip you will see a directory called
"install". Extract this directory from the zip file onto your local computer
and upload to your forums root directory.
Then run
http://www.domain.com/install/update_to_211.phpDelete the install folder from your forums root directory.
This will update your database.
I think that will do it, and you should now have a updated version of phpbb.

This is great - if you're using a standalone of the forum. But what about those of us who are using phpNuke with phpBB integrated into it?
I can't for the life of me figure out how to upgrade the Forums so this hack can be safeguarded against. Ideally, I'd like to upgrade to phpNuke 7.5 but I'm skeered!