How to change your Instagram username
How to change your Instagram username: Open the Instagram app. Go to your profile. Your username appears above your avatar. To change it, click the Edit Profile button.
Here you can change your name and username. Click the field with your username. Delete your old one and enter a new one.
Note that in most cases, you will be able to change your username back to your old one within the next 14 days.
Click the checkmark icon in the upper right corner.
Note that after changing your username, mentions of your old username in comments or other people's posts will no longer link to your profile.