Hi all, I found the solution about how change the country code of your AirPort Extreme, I had bought used boxes and they were set to another region code compare where I m living, so you need to ssh access to change this and choose which canal you want to use (allowed by country code), plus you have access to fan speed, temps...Etc....
Thank you very much Ray Haverfield for your help to achieve this.
For more succinct answer, a python module https://github.com/samuelthomas2774/airport/wiki/AirPyrt#installation is needed to communicate with with the AirPort. So a copy-paste code block should be: cd ~
git clone https://github.com/x56/airpyrt-tools.git
cd airpyrt-tools
python setup.py install --user
and not so copy-paste followup (need to supply your own airport and password: python -m acp -t {ipv4-address} -p {password} --setprop dbug 0x3000
python -m acp -t {ipv4-address} -p {password} --reboot