Complex sentence: On 6 March 1945, Reymann was telephoned by Hitler's Chief Adjutant, General Wilhelm Burgdorf, and ordered to take command of the defenses of Dresden.
Split into simpler sentences: On 6 March 1945, Reymann was telephoned by Hitler's Chief Adjutant, General Wilhelm Burgdorf. Burgdorf ordered Reymann to take command of the defenses of Dresden.