Clone into ext/phpbbde/tou:
git clone https://github.com/phpbb-de/phpbb-ext-tou ext/phpbbde/tou
Go to "ACP" > "Customise" > "Extensions" and enable the "phpBB.de tou" extension.
If you find a bug, please report it on https://github.com/phpbb-de/phpbb-ext-tou
We will use automated unit tests including functional tests in the future to prevent regressions. Check out our travis build below: