OK it looks I'm finally managed to reach my goal here. It was a lot of work but I've learned a lot new stuff.
Thanks to Kirk for pointing me in the right direction.
view my result on http://www.lambrettaforum.eu

OK I did this step and visited /install/index.php, there I choose uninstall and get a confirmation that the board was uninstalled and also this note; 'Remember to delete the Portal-related files and reverse any Portal-related edits made to phpBB core files.' In fact so far I don't see any difference...

I uploaded again the original v1.0.3 (not 1.3 like a said earlier) install files to the forum, but when viewing the install.xml, all I see are the instructions how to upload and modify files. There is no expalantion how the database tables are modifoed for this setup of board v1.0.3. So how can I un...

Since I'm on a new hosting with a default phpbb install, I think all v1.3 files are 'removed', but maybe the database table are causing problems? How can I solve this. Do I manually need to clean up the database? Also the install af the new version v2.0.2, do I really need to cope each file manually...

Your Portal Version: v2.0.2 Your phpBB Type: Standard phpBB3 MODs installed: No Your knowledge: Basic Knowledge What have you done before the problem was there? I'm moving my b-board (phpbb 3.11 & board v1.3) to a new hosting. There I have a standard setup phpbb 3.12 ready. I imported the DB an...