It all depends on when your TV was manufactured, some work out of the box and some need the upgrade. If you do need an upgrade Sony sends the tech to your house. When I had mine done they even gave me a $100 Sony gift card, the only downside is you can't use the gift card on 4K movies, it had to be used at the sony store.
The upgrade requires the back of the TV to be removed, so if you've hung your TV they will need to pull it off the wall, what I did is had the TV stand for them so they unmounted my TV, used the stand and then re-mounted it after they diid the upgrade. They will also need to load firmware and run though a setup, it took around 2 hours from the time they showed up to the time I was watching the media player.