Multi subnet failover cluster setup

Hi.

1. Cluster services already created also working with multi subnet failover cluster
2. Total three Nodes, Two Nodes hosted in Primary site and One Node hosted at Remote Site all the nodes are installed OS version is windows 2012 standard edition in HyperV machine.
3. There is no shared storage attached, all three node local virtual Hard Disk.
4. FSW – file share witness created at Primary site not in Remote site.

1. I want to test failover scenario if totally primary site down including FSW then how will start cluster service in Remote site DR node. And what are the mandatory steps should be followed?

Please help.

Thanks