The login email / username for an account cannot be changed.
If you have products registered on your account, you may log in to the old Revulytics Usage Intelligence Product Dashboard, go to Administration & Settings> Users & Permissions, and send an invite to the new email address you'd like to use. An invitation will be sent to the specified email address, from which you can accept the invite and register a new account which will have access to the same product.
If you do not have a product registered on your account, you can create an account with a different email address and continue to use the new account.
If you have created a new account and would like to deactivate your old user account, please contact support.