title: Modifying the genesis block using configtxlator
body: <p>I'm a little confused as to how to modify the system channel configuration once the Fabric network is operational.</p>
  
  <p>I gather that the <code>configtxlator</code> tool can be used to create a patch transaction with the necessary changes, but how is this transaction then applied to the system channel?  Can the <code>peer channel update</code> CLI tool be used for this?</p>