DOCS-4828 auth fix

source/tutorial/change-hostnames-in-a-replica-set.txt

@@ -222,6 +222,33 @@ This procedure uses the above :ref:`assumptions  <procedure-assumption-change-ho
 
          mongo --port 37017
 
+   #. **If** :ref:`authorization` **is active**, log in as a user with
+      the :authrole:`userAdminAnyDatabase` role and issue the
+      following commands to create a user role capable of modifying
+      the ``local.system.replset`` collection:
+
+      .. code-block:: javascript
+
+         db.runCommand(
+           { createRole: "replsetRole",
+             privileges: [
+               { resource: {db: "local", collection: "system.replset" },
+                 actions: [ "find", "update", "remove" ]
+               }
+             ],
+             roles: []
+           }
+         );
+
+      Once this role is created, grant the role to a user:
+
+      .. code-block:: javascript
+
+         db.grantRolesToUser( "<username>", [ { role: "replsetRole", db: "admin" } ] );
+
+      and log in as that user. You may grant the role to the user
+      being used to create the role, if appropriate.
+
    #. Edit the replica set configuration manually. The replica set
       configuration is the only document in the ``system.replset``
       collection in the ``local`` database. Edit the replica set