So, how ???

You can't. Post your request(s) in the 'fix me beautiful' thread and someone will take care of it. :)

To be fair, we do understand that there needs to be a better system for adding information like that or telling admins about information that is incorrect, which is why there is a ticket for such functionality in the GitHub issue tracker, in fact:

https://github.com/demozoo/demozoo/issues/104