Gotten tired of your gamer-tag or want to change your in-the-moment gamertag? That is no problem! You can easily change these settings in your Profile Settings as necessary:
Click your profile icon in the bottom-left corner on smash.gg
Click Profile Settings
Click Change Gamertag and type in your new tag
Important Note: You may only edit your gamertag once every 30 days. This is intended to provide a degree of consistency when viewing past tournament results.