You can create new VPN Connections or edit an existing one in your VPC by following these steps:
Go to the VPN Connections tab, select Cloud Account and Region of your desired VPC and click on Create VPN Connection.
Add a Customer Gateway, a VPN Gateway and select the type of Routing (Static or Dynamic)
In case of Static Routing enter a Destination CIDR Blocks Address.
Next, set the Tunnels for your VPN Connection.
Following steps will be required in order to create a Tunnel:
Enter a Pre Shared Key and Tunnel Inside CIDR.
Select your Phase 1 and Phase 2 Encryption Algorithms.
Next, select Integrity Algorithms for each Phase.
Add DH Group Numbers for each of the two Phases.
Select the IKE Versions and then set Lifetime, in seconds, for each Phase.
Set ReKey Margin Time and ReKey Fuzz Percentage.
Set the packets of Replay Window Size and seconds for DPD Timeout.
Once done, click Add to create the Tunnel.
You can also add a specific Tag for your VPN Connection. Once done, Click on Create.