Who changed the rules for Valkyrie in world war II during Hitlers rule

On July 20, 1944, Claus Schenk Graf von Stauffenberg, an aristocratic colonel in the Nazi army, took the fate of the German people into his own hands. Increasingly disillusioned with Hitler's campaign in the war, Stauffenberg and numerous other co-conspirators within the German military, including Friedrich Olbricht and Henning von Tresckow, plotted to assassinate the dictator and seize the reins of power.