A practical walkthrough on downloading and installing updates via the Palo Alto Networks Support Portal . This would cover the basics of checking for releases and manual uploads.
This review is written from the perspective of a network security engineer or administrator. palo alto firmware
You cannot jump versions. Upgrading from 9.1 to 11.0 might require (9.1 → 10.0 → 10.1 → 10.2 → 11.0). Each reboot takes 5-15 minutes. This turns a simple upgrade into a 2-hour maintenance window. palo alto firmware