How to change Region 1 to Region 4 on a Denon 2910

I recently purchased a Denon 2910 in the USA to take to Brazil where I'm moving permanently in about 5 weeks. A friend who also bought the same unit and also moved to Brazil had provided me with a code to be able to change the unit from Region 1 to Region 4 (used in Brazil). However, Denon apparently changed the code and I can no longer make the switch. I have extensively surfed the internet looking for answers even entering Brazilian forums. I have also followed the long string of posted feedbacks at AVforum, but all the suggestions seem to be directed to those trying to change to Region 2, which is absolutely of no use to me. The firmware tinckering also being suggested by some at that site, does not guaranteed to put me into Region 4, and worse, it can actually damage the 2910 which I'm not about ready to do. There is also a site: that provides step by step instructions on how to convert to Region 2, which by the way, it doesn't work at all with the new Region I - 2910 units. If anyone knows how to successfully change the code but without firmware changes, please let me know - Thanks!