QOS or Traffic Management setup help needed...

I have two sites.  Both sites have x1250e.  I connect them via BOVPN.  Each of those two sites have two networks.  One network in each site hosts an iSCSI san, the other network is a production network used for connections back and forth between the two sites (AD, filesharing, printing, etc).  Throughout the day, I replicate data between the two iSCSI networks.  When this happens the replication traffic crowds out all the other traffic passing through the BOVPN tunnel.

I would like to use QOS or traffic management to keep this from happening.  Unfortunately for me, I'm having a hard time making sense of the documentation.  Can someone give me some guidance?

So far, I've created two separate tunnels.  I've created tunnel a for traffic between the production networks, and I've created a separate tunnel for traffic between the iSCSI networks.

What is my next step?

Thanks in advance for you help!