Download the “Patch file only” package from the phpBB.com download page, and extract it to a folder somewhere at your hard drive
Select the correct patch, e.g. if your current version is 2.0.14 you need the phpBB-2.0.14_to_2.0.17.patch. Place the correct patch in the parent directory of your board (the one containing the phpBB core files like index.php, viewforum.php, etc.)
Upload the update_to_latest.php file to the /install directory of your board. If the directory doesn't exist you'll have to create it
Run the following command using the command line:
patch -cl -d [PHPBB DIRECTORY] -p1 < [PATCH NAME]
where PHPBB DIRECTORY is the directory name your phpBB board resides in and where PATCH NAME is the filename of the patch file which you would like to execute.
This should complete quickly, hopefully without any HUNK FAILED comments.
If you do get failures you'll have to try the next update method described in this article. Alternatively if you know how you can examine the .rej files to determine what failed where and make manual adjustments to the relevant source
Delete the patch file (or files)
Run install/update_to_latest.php trough your browser (using http://www.domain.com/phpBB2/install/up ... latest.php
, for example)
This will update your database schema and data (if appropriate) and increment the version number
Delete the /install directory from your board's root directory