The Amazon Fire TV (2015) adds smart TV features and 4K Amazon content to any 4K TV. The Sony Bravia LED 4K Smart TV already has Google Android's smart TV features, but you can still use the Amazon Fire TV to more easily find Amazon's 4K content.
Use a certified HDMI cable to connect the Amazon Fire TV to any of the Bravia 4K TV's HDMI 2.0 ports which support 4K@60Hz. Once you plug in the HDMI cable, go to the inputs on your Bravia TV and select the the Amazon Fire TV which shows up as one of the HDMI inputs.
Next you need to make sure that your Fire TV is connected to the Internet. Make sure your Internet connection has at least 20 Mb/s download speeds to stream 4K video.
To set up network, go to Amazon Fire TV Settings -> System -> Network, and select any available WI-FI Network.
Once you are connected to the Internet, you can happily browse videos from the Fire TV to the Bravia 4K TV.
The Amazon Fire TV (2015) HDMI 2.0 connection works well with the Sony Bravia LED 4K Smart TV, enabling 4K@60Hz playback of all your favorite Amazon 4K shows. The power of Android TV and Amazon TV combined should be more than enough to cover all your online content, Apps, and 4K video needs.