Here are the steps to delete the IPsec configuration:
On the VPN page, in the More column, select Configuration.
Select the IPsec tab. Make sure the Connection Status is disconnected and click More then click the Delete button.
Press the Confirm button to continue the process of deleting the IPsec configuration.
Wait until the process is complete.
A notification appears "IPsec configuration [IPsec-name] has been successfully deleted".