Here's what worked for me:
- Unplug wireless network
- Press reset button on TV
- Turn TV back on
- When it asks for connect to network information, select DO LATER. On following screens, if prompted, select LATER
- Once you get to home screen, go to settings, advanced settings, then FACTORY reset.
- Once a factory reset was done, I was able to finish the update
This will get you out of the STUCK mode.
