doc(registration): update registration for 2.3 behavior (#448)

* doc(registration): update registration for 2.3 behavior

* doc(registration mode): must use may

Author: slack

src/users/registration.md

@@ -61,24 +61,14 @@ Deis Workflow supports three registration modes:
 | disabled          | Does not allow anyone to register new users.    |
 | admin\_only       | Only existing admins may register new users     |
 
-To modify the registration mode for Workflow you must add or modify the `REGISTRATION_MODE` environment variable. If
-Deis Workflow is already up and running, you may use `kubectl --namespace=deis edit rc deis-controller`:
+To modify the registration mode for Workflow you may add or modify the `REGISTRATION_MODE` environment variable for the
+controller component. If Deis Workflow is already running, use `kubectl --namespace=deis edit deployment deis-controller`:
 
 Find the `REGISTRATION_MODE` environment variable in the template file or add the appropriate section:
 
 ![](../images/controller-registration-mode.png)
 
-Once you save the Replication Controller configuration, you need to find and delete the controller Pod.
-
-```
-~ $ kubectl --namespace=deis get po | egrep deis-controller
-deis-controller-lto6v         1/1       Running   1          2h
-~ $ kubectl --namespace=deis delete po deis-controller-lto6v
-pod "deis-controller-lto6v" deleted
-```
-
-Kubernetes will automatically start a new Pod with the new environment variables set. Note that you will incur downtime
-for the Workflow API only. All running applications will continue to function.
+Kubernetes will automatically deploy a new ReplicaSet and corresponding Pod with the new environment variables set.
 
 ## Managing Administrative Permissions