Ok, beside the wiki (www.osticket.com/wiki) here's a little guide how to upgrade:1. BACKUP, BACKUP, BACKUP!Really important!Backup the mysql database and also backup the osTicket installation directory.2. Take the helpdesk offline (Admin Panel -> Settings -> System -> Helpdesk Status -> Offline)3. Download osTicket 1.9.3 (http://www.osticket.com/download is recommended/official download page)4. Extract the 1.9.3 archive5. Copy all files from the folder "upload" over your osTicket installation directory6. Login to /scp with an admin account7. Database upgradeA) IF there are any updates that need to modify the database, you will now be redirected to the upgrader (/scp/upgrade.php)B) IF NOT, no upgrader is appearing, you should navigate to Admin Panel -> Dashboard -> Information and see the new osTicket version there.8. Take back the helpdesk online (Admin Panel -> Settings -> System -> Helpdesk Status -> Online)9. TEST, TEST, TEST. Now it's time to test if everthing is ok. Important step at the end. You can e.g. create a ticket through web, email, api (if used), in the scp, reply to a open ticket, and so on to make sure everything works like it should. Beside that check the osTicket logs (Admin Panel -> Dashboard -> System logs) and maybe your PHP / Webserver logs if everything is ok.10. Done. You did the upgrade (: