Complex sentence: For about a year, he stayed in Muonio (in the valley of Tornio river), a remote village at the Lapland living in the rectory under the name Müller as a guest of the local Lutheran vicar.
Split into simpler sentences: For about a year, he stayed in Muonio, a remote village in the valley of the Tornio river in Lapland. He lived in the rectory under the name Müller, as a guest of the local Lutheran vicar.