All StarCraft II accounts have been granted one free name change. If you'd like to change your character name, log in to Account Management and select your StarCraft II game license from your list of game accounts.
You can use the dropdown list in the "Character Name Change" section at the bottom of your game license screen to select a region in which you'd like to use an available name change. Once you've selected a region, click the "Use Name Change" button to initiate the request. After confirming that you'd like to change your character name, simply log in to StarCraft II and you'll be prompted to select a new one.
We’d like to remind you that free name changes do not stack. Today’s name change will replace any unused name changes that were previously available for your account. We’re also re-evaluating our approach to the name change process internally in order to offer free name changes much more frequently going forward. We’ll have more details on this at a later date.