If you do not use the customer gateway anymore and haven’t created any VPN tunnels, you can delete the customer gateway.
Directions.
1. Log in to the VPC console.
2. In the left directory, click VPN Connections > Customer Gateway to enter the management page.
3. On the "Customer Gateway" management page, click Delete on the right side of the customer gateway instance to be deleted.
4. In the confirmation dialog box, click OK to complete the operation.