Sentence:  Nazi-era Schlager are thus reappropriated as part of the FRG after 1989 and help to <WSD>self-colonize</WSD> the previously alien(ated) nation of Germany for the Germans. 
Meaning of the word marked with <WSD> tags:  To regain power (by indigenous people) after having been under colonial rule by another country, typically with the adoption of some of the culture of the former colonizers.