If you can unlock the bootloader, it might be possible to install a Halium distro like Droidian on it. I wouldn't recommend doing so, however, and there will be missing functionality, such as being able to use any video inputs or watch live TV. It will basically be a large smartphone without a touchscreen.
Instead, I recommend disconnecting your TV from the internet and connecting an external device to it as others have recommended. See if there's a way to autoboot your TV to an HDMI input. You can also get a USB CEC adapter to use your TV's remote on your external device for something like Kodi, for instance.