WordPress.org

1. Extract the archive
2. upload the phpbb-sso directory to the /wp-content/plugins/ directory
3. Activate the plugin through the 'Plugins' menu in WordPress
4. Configure the path to PHPBB in the options
5. When the path is right some fields related to phpbb will appear, fill them and save.
6. Click on "install files" to install files.
7. If all tests are OK you cant logout and login to test.

How to configure ?

there are three ways to configure it.

In the example, the root of the website is "/www/"

Example 1

Blog : /www/ Forum : /www/forum/

Path to configure: To PHPBB from WordPress : forum/ To WordPress from PHPBB : ../

Example 2

Blog : /www/blog/ Forum : /www/

Path to configure: To PHPBB from WordPress : ../ To WordPress from PHPBB : blog/

Example 3

Blog : /www/blog/ Forum : /www/forum/

Path to configure: To PHPBB from WordPress : ../forum/ To WordPress from PHPBB : ../blog/