Upgrading from version x to version y is simple as overwriting the old Ortro installation directory with the new one.
Just remember to check ownership and permission especially for the configuration directory (i.e. conf).
# chmod 700 $ORTRO_HOME/conf
When the upgrade require to alter the database structure, you will find a folder with the relative scripts, enter in the folder and exec the upgrade.php script:
# cd $ORTRO_HOME/upgrade # php upgrade.php