Go to the Match website. Click inside the Sign In box and type your current username. Press the tab key and enter your password. Select the blue "Sign In" button.
Locate the "Account" link at the top of the page and select it. Scroll down the Account Settings page. Click on "Sign Up Information." Enter your password in the box and choose "Go."
Select the "Change Sign Up Info" button. Delete your current username from the box labeled "Choose a Username" and type the screen name you desire. Make sure your new name is correct. Click "Continue." If the screen name you selected is already in use, pick another one. Otherwise, you'll receive a message stating that you have successfully changed your information.