1.11 to 1.12 is a very straightforward upgrade.
- Assuming your osTicket Awesome installation is in a directory named /support, rename it to /support-backup.
- Upload the the 1.12 /upload folder, rename it to /support.
- Copy over your /support-backup/include/ost-config.php file from to /support/include/.
The upgrade is complete but unfortunately any osTicket Awesome settings will have to be manually recreated.
Incidentally the next release will move all settings into the database to simplify things going forward.