Step 1 – Enable ADB on your device:
Install Android TV Launcher from here (all credit to tsynik)
Install the renamed Launcher hijack from here
Install the SettingsTest from here
Install Remote ADB on to your firestick from here
Open up Remote ADB Shell and type in the IP address 127.0.0.1 the port will be 5555
Once connected, enter in the following commands (case sensitive)
pm grant com.example.settest.settingstest android.permission.WRITE_SECURE_SETTINGS
Press home and find the “settingstest” application (it looks like a green android logo) open it up
The app will open and you will see a “settings saved” prompt. This means everything has worked correctly
You can now click on the leanback launcher to set that as default
You will now see the Android TV launcher
How to undo the process and restore the Amazon Launcher
Open up ADB again and enter in the following command
settings delete secure enabled_accessibility_services
You will see a message like
Press the Home key and you will back to your default launcher
Watch the video here: