Hello desmond,
You're probably familiar with the process already but click on the link and read how to "Change your Apple ID country or region" - https://support.apple.com/HT201389
There is no way to quickly do that. The system just isn't set up that way and if anything is set up to discourage people who want to change to another country just because something isn't licensed for use in their country.
Germany must have changed. When I lived there the Germans had very strict definitions of where you "resided". You could even have residency in two cities, much less two countries.