Complex sentence: In late-1944 Hahn was promoted to the rank of SS-Standartenfuher (colonel) and reassigned to the Western Front and stationed in the Rhenish town of Cochem, where he served as commander of "Einsatzgruppe L" during the Battle of the Bulge.
Split into simpler sentences: In late-1944 Hahn was promoted to the rank of SS-Standartenfuher (colonel) and reassigned to the Western Front. He was stationed in the Rhenish town of Cochem and served as commander of "Einsatzgruppe L" during the Battle of the Bulge.