Not sure you can, not even I have the option to edit it for you. Mines also locked to my gmail which I dont rememebr telling it.
It’s a really difficult to change an account’s e-mail because everything is connected through it. Discourse officially does not support it, but I can change it manually if there is a really good reason to do so, for example: mail is not in use any more. If this is the case, please send me a PM with a new e-mail address and I will do it. If you are accessing your account through Facebook or Google login, then you should first change your e-mail/account there.
also: how to change one’s password?
not seeing a section for that in the profile settings