Add documentation on resetting user passwords

docs/howto/auth/firstuse.rst

@@ -34,3 +34,37 @@ the JupyterHub, run the following command.
 
    tljh-config set auth.FirstUseAuthenticator.create_users true
    tljh-config reload
+
+
+Resetting user password
+=======================
+
+You can reset user passwords by *deleting* the user from the JupyterHub admin
+page. This logs the user out, but does **not** remove any of their data or
+home directories. The user can then set a new password by logging in again with
+their new password.
+
+#. As an admin user, open the **Control Panel** by clicking the control panel
+   button on the top right of your JupyterHub.
+
+   .. image:: ../images/control-panel-button.png
+      :alt: Control panel button in notebook, top right
+
+#. In the control panel, open the **Admin** link in the top left.
+
+   .. image:: ../images/admin/admin-access-button.png
+      :alt: Admin button in control panel, top left
+
+   This opens up the JupyterHub admin page, where you can add / delete users,
+   start / stop peoples' servers and see who is online.
+
+#. **Delete** the user whose password needs resetting. Remember this **does not**
+   delete their data or home directory.
+
+   .. image:: ../images/auth/firstuse/delete-user.png
+      :alt: Delete user button for each user
+
+   If there is a confirmation dialog, confirm the deletion. This will also log the
+   user out if they were currently running.
+
+#. Ask the user to log in again with their new password as usual.