because i have logged in with facebook my username is my e-mail adres 
I can’t change it. Can somebody please do that?
You can change your forum username and hide your email address on the accounts page at Plex.tv.
Is this what you’d like to do?
Plex.tv -> My Account -> Settings
Thank you so much 
I see you already have a username. Visit https://forums.plex.tv/sso and your username will update.
