How to make the Panasonic DVP520 DVD player multi-region

I was recently given a Region 1 Godzilla DVD of Destroy all monsters. (Amazon claimed it was Region 0 but it turned up as region 1.) A spot of googling revealed how to get the DVD to play in our Panasonic DVP520

1. Make sure there’s no DVD disc in the drive
2. Press system menu on remote control
3. Go to preference settings
4. Press 1,3,5,5,6,6
5. Press 0
6. Press system menu on remote to exit

Panasonic DVP520 DVD player

Destroy all monsters