Usually that means trying to get Android TV working through USB, but it depends on what tv you have. If you already have an Android TV, just use a launcher like Projectivy. Most people just buy a media box: either an Android based one or apple tv and disable the "smart" tv altogether
I'd imagine you could probably get into the android developer settings and disable all the telemetry stuff through adb and install a custom launcher like projectivity and that'd be the closest you could get to running a custom tv OS at least if you can't flash it.