From Zarafa wiki
In order to update z-push2 you can download the new .tar.gz from http://z-push.org The info on this page is NOT to be used to upgrade from version 1.x to version 2.x of z-push.
Required: login as root or use sudo.
In this example x-yyyy is replaced for the version number.
We will assume that you installed Z-Push in /var/www/z-push but some documentation or distributions use /usr/share/z-push.
Important: The state folder should be kept when updating Z-Push.
Read the release notes, as there could be special things which require attention!
Make a backup of your installation inclusing config.php because new settings and defaults may change, please perform backup and upgrade using the following steps.
wget http://zarafa-deutschland.de/z-push-download/final/2.0/z-push-2.0.x-yyyy.tar.gz tar -zxf z-push-2.0.x-yyyy.tar.gz mv z-push-2.0.x-yyyy /var/www/ diff /var/www/z-push/config.php /var/www/z-push-2.0.x-yyyy/config.php
Check your config.php and possible modified defaults and update the new config.php by hand in the /var/www/z-push-2.0.x-yyyy directory.
Then mv the old version and make a symbolic link to the new version:
mv /var/www/z-push /var/www/z-push.old ln -s /var/www/z-push-2.0.x-yyyy /var/www/z-push
After completing these steps, your Z-Push will be up-to-date and all new connections will use the new z-push version.
To check the current version you can execute (where /var/www/z-push/ is where you installed Z-Push):
grep VERSION /var/www/z-push/version.php
After that open a browser and get this URL, press CANCEL when the browser asks for a login.
or with SSL use https:
That should output something like this: