Zarejestrowani i zalogowani uzytkownicy moga usuwac pliki na swoim koncie w sekcji Moje konto/Moje pliki.

We cannot establish that you are the uploader of the file(s) if you were not registered, logged in, and no longer have the delete link.
Therefore the file will be deleted automatically 30 days after the last download. You do not need to do anything further.