In the past you could change the country inside the AdSense interface by changing your billing address but that is not working anymore. But if you are earning enough, i.e. at least $25 per week over the last five weeks there is another method.

If you go to [support.google.com...] while you are logged in in your AdSense account, you can click the "Contact Us" link in the right top of your screen. Click that link and select "Account" from the menu. If a country switch is possible for your account (in some countries accounts are locked for transfer) you can click the "Change of Country" option which will guide you through the rest of the process.

Thank you Lammert, trough the support page I could contact Google Adsense and they responded quit fast, it seams that I need to open a new account because I can not change the country name in the country where I lived! When I have open the new account they are going to close the old account and transfer my unpaid payments to the new account!

Good to hear that support responded so fast. They have to obey local laws which sometimes cause these non-logical issues where in the open market of the EU you apparently can't transfer an AdSense account between these two neighboring countries. It feels a little bit strange though because a few years ago I was able to move my account from the EU to Asia without having to close it.

I think the local law must be from Germany, because I have moved 4 years ago without a problem from Spain to Holland, and 2 years ago from Holland to Germany.