Please note this install guide was done on an Nvidia Shield device your AndroidTV may vary but the concepts here on how to install should be similar.
1. From you devices home screen go to your apps menu option
2. Press the Arrow down button to get to the " Open the Google Play store" button and press the "Enter / Okay" button on your remote.
3. Goto the search icon and select "Search"
4. Enter "OAN Live" into the search field
5. Select the "OAN Live" app and press the "Enter / Okay" button on your remote to open the app details page
6. Click the install button to install the app
7. Once the install is complete you can click the open button to launch the app. See How to Login to "OAN Live" on Android TV Devices for more information on how to Logon.