Upgrading the firmware is very complex

[jolouis]

Lazy are we? If you open the document and actually look at it you'll notice that it' 20+ pages because it describes all of the various methods that you can use to update the firmware and provision the phone.

If you want a single straight forward upgrade, just log into the web interface on the phone, go to the config page and hit "Upload new firmware"... doesn't get easier than that.

If you're doing multiple phones you need to setup a basic provisioning system. If that's out of your comfort zone then stick to doing it manually, it'll be faster than teaching yourself how provisioning works.