:salam2:
Usernames can be changed by the Admin only. Therefore brother Mabsoot is the right person to be contacted. Once he comes across this request, he will try to contact the member if there is a possibility of a username change.
As you would imagine, brother Mabsoot is already preoccupied with a lot of tasks related towards smooth running and improvement on TTI so it might take him a while to get through with various user requests for account changes and so on. So please bear with patience for the time being. JazakAllahu Khayran