Just let me know.
It's something I can do, and have done in the past.
Assuming I approve of the change, I can do it easily enough.
You would have the same exact account, post history, etc. Only the name would change.
If your old account is old enough, or has a significant number of posts, I might put your old name below your new name (as a subtitle -- like the word "Moderator" on my own) to help avoid confusion.