You can do it yourself from within your user profile.

Click on the favicon on the Stack Exchange yo bar (hovering over it with your mouse will show you current username).

This will take you to your Activity page and click on the menu option Profile at the top.

Here, under your Username and to the right of your chose favicon you will see in red Click here to edit.

After clicking on this option you will be able to edit your name as required (and change your picture to something else if desired) then go to the bottom f the page and select as required "Save changes just for this community" or " Save and copy changes to all public communities".

You can do it yourself from within your user profile.

Click on the favicon on the Stack Exchange yo bar (hovering over it with your mouse will show you current username).

This will take you to your Activity page and click on the menu option Profile at the top.

Here, under your Username and to the right of your chose favicon you will see in red Click here to edit unless you already have some text in 'about me' in which case you may have to click on Main User over on the right to give access to Edit profile and settings as shown in graphic 2 below.

After clicking on this option you will be able to edit your name as required (and change your picture to something else if desired) then go to the bottom f the page and select as required "Save changes just for this community" or " Save and copy changes to all public communities".