Re: how to upgrade BB9780
dowmload and install desktop manager and connect your bb to your pc.
Providing your pc is connected to the internet the desktop software should let you know what upgrade is availqble.
be careful with the social feeds app as this sometimes scews your backup. I upgraded my 9790 and ended up removing the app from the bb to get the upgrade to work. don't worry though as it gets reinstalled.
I ways backup first anyhow, even though the upgrade completes one anyhow. also you will need to login to all your apps (facebook twitter app world, etc) once upgraded.