SQL 2012 replication between subscribers on a VPN

I've been assigned the replication configuration for an instance (remote instance) on a geographic location to which we have access via a VPN. The remote instance will have to send the transactions to a subscriber / local distributor (subscription 1), then the transactions of this subscription will have to be extracted / pushed to an on-site instance (subscription 2).

I have problems figuring out the steps to follow to configure the subscription 1 subscription configuration 2. The contributions are greatly appreciated.