diff --git a/source/upgrade-guide/index.rst b/source/upgrade-guide/index.rst
--- a/source/upgrade-guide/index.rst
+++ b/source/upgrade-guide/index.rst
@@ -8,6 +8,7 @@
 .. toctree::
     :maxdepth: 1
 
+    kolab-16
     kolab-enterprise-14
 
 .. toctree::
diff --git a/source/upgrade-guide/kolab-16.rst b/source/upgrade-guide/kolab-16.rst
new file mode 100644
--- /dev/null
+++ b/source/upgrade-guide/kolab-16.rst
@@ -0,0 +1,119 @@
+==================================
+Upgrade Notes from Kolab 3.4 to 16
+==================================
+
+The purpose of this document is, to describe the procedure of upgrading a Kolab Goupware installation from a default installed Kolab 3.4 (last "community verison") to Kolab 16.
+
+
+Upgrade Procedure
+=================
+
+#.  Install the Kolab Groupware repository configuration:
+
+    .. parsed-literal::
+
+        # :command:`cd /etc/yum.repos.d/`
+        # :command:`wget http://obs.kolabsys.com/repositories/Kolab:/16/CentOS_7/Kolab:16.repo`
+
+#.  Remove the existing Kolab 3.4 repositories:
+
+    .. parsed-literal::
+
+        # :command:`rm Kolab\\:3.4.repo`
+        # :command:`rm Kolab\\:3.4\\:Updates.repo`
+
+#.  Make sure that the packages from the Kolab repositories have a higher priority than eg. the :term:`EPEL` packages:
+
+    .. parsed-literal::
+
+        # :command:`for f in /etc/yum.repos.d/Kolab*.repo; do echo "priority = 60" >> $f; done`
+
+
+#.  Replace php-mysql with php-mysqlnd:
+
+    .. parsed-literal::
+
+        # :command:`yum shell`
+        > :command:`remove php-mysql`
+        > :command:`install php-mysqlnd`
+        > :command:`run`
+        (Confirm as requested)
+        > :command:`exit`
+
+#.  Update all:
+
+    .. parsed-literal::
+
+        # :command:`yum -y update`
+
+
+    .. NOTE:: During the cleanup, you might see the message:
+
+        .. parsed-literal::
+
+            `/var/tmp/rpm-tmp.TUmak9: line 1: fg: no job control`
+            `Cleanup    : cyrus-imapd-2.5-108.3.el7.kolab_3.4.x86_64                                               347/404`
+            `/var/tmp/rpm-tmp.K51Mal: line 2: fg: no job control`
+            `warning: %postun(cyrus-imapd-2.5-108.3.el7.kolab_3.4.x86_64) scriptlet failed, exit status 1`
+            `Non-fatal POSTUN scriptlet failure in rpm package cyrus-imapd-2.5-108.3.el7.kolab_3.4.x86_64`
+
+        This is a warning, and the Cyrus-imapd package will be updated. This can be checked after the update with the command:
+
+        .. parsed-literal::
+
+            # :command:`rpm -qv cyrus-imapd`
+
+
+
+Updating the Configuration
+==========================
+
+After upgrading the packages to Kolab 16 repository, the configuration needs to be updated.
+
+1.  Configure the new module "Guam":
+
+    .. parsed-literal::
+
+        # :command:`setup-kolab guam`
+
+2.  Configure the new module "Manticore":
+
+    .. parsed-literal::
+
+        # :command:`setup-kolab manticore`
+
+    .. WARNING::
+
+        If the Kolab 3.4 installation was a standard installation with no changes to the defaults, then the following 2 commands can be run at no risk (The correct password for the current roundcube database user is still needed for verification).
+
+        However, if changes were made to the defaults, the original configuration should be copied off for later compare with the newly written configuration.
+
+3.  Update the roundcube configuration:
+
+    .. NOTE::
+
+        As setup-kolab is unable to write to the already existing mysql database, an error message will show:
+
+        .. parsed-literal::
+
+            `ERROR 1007 (HY000) at line 1: Can't create database 'roundcube'; database exists`
+            `ERROR 1050 (42S01) at line 8: Table 'session' already exists`
+
+        The new and updated config file will however be written and restart the appropriate services.
+
+        The correct password for the current roundcube database user is still needed for verification.
+
+    .. parsed-literal::
+
+        # :command:`setup-kolab roundcube`
+
+
+
+4.  Update the imap configuration:
+
+    .. parsed-literal::
+
+        # :command:`setup-kolab imap`
+
+
+