If you've made less than 20 posts, you can change your username by submitting a help request (https://www.forexfactory.com/contact.php?subject=help). If you have more than 20 posts, your username cannot be changed unless there are substantial privacy concerns.
How do I delete my username?
If you've made less than five posts, you can have your username deleted by submitting a help request (https://www.forexfactory.com/contact.php?subject=help). If you have more than five posts, your username cannot be deleted, as it would disrupt the conversations in which you've participated.