Prepare your butt is all I have to say....

It's not Android TV. It's Android, and Android 4 versions ago at that. Advice: throw it in the bin and get a real Android TV device.

Cue the weekly dumbass alert

running andriod 4.2.1

Jesus fucking Christ. This is why we don't recommend Android boxes. You're using an OS from over 4 fucking years ago. Get a real Android TV device.

Download and copy TWRP to an SD Card along with your with new image.

Here's another method using USB to USB cable .

Android TV image and discussion...

Alternately, you can install Linux .

I suspect it is running android not andriod tv so you won't get much help here

You know those boxes have a service called fotaprovider which calls home to China right?

Reason # 332 in a series of 1740 to avoid generic chinese tv boxes....

throw it in the bin