Submittable has a great help page to walk you through changing your profile information.
You can even change the contact name and email associated with your account, which is helpful if you are an organization whose staff has changed. You will want to make sure you do so before you lose access to that staff person's email, as you will need to login to Submittable to be able to make the change. If you do not have access to the email account, contact Andrea.