Add documentation for upgrading servers

source/servers/upgrading.rst

@@ -1,3 +1,30 @@
 Upgrading
 =========
 
+Upgrading UH VPN Server software is simple and is done via the apt package manager on Ubuntu.
+It is worth noting that this operation will restart all VPN servers in operation on the machine,
+having the effect of disconnecting all connected clients which will then subsequently reconnect
+after a period of around one minute.
+
+The first step is to update the package archives:
+
+.. code-block:: bash
+
+    $> sudo apt-get update
+
+To upgrade just UH VPN Server software issue the command:
+
+.. code-block:: bash
+
+    $> sudo apt-get install uh-vpn-server
+
+This will install any updates for the uh-vpn-server service or alert you if you are already
+on the latest version.
+
+**Alternatively**, UH VPN Server software is also upgradeable via the command:
+
+.. code-block:: bash
+
+    $> sudo apt-get upgrade
+
+However, doing so upgrades other packages already installed on the system.