Complex sentence: Milch quickly used his position to settle personal scores with other aviation industry personalities, including Hugo Junkers and Willy Messerschmitt; specifically, Milch banned the latter from submitting a design in the competition to choose a modern fighter aircraft for the new "Luftwaffe".
Split into simpler sentences: Milch quickly used his position to settle personal scores with other aviation industry personalities, including Hugo Junkers and Willy Messerschmitt. Specifically, Milch banned Messerchmitt from submitting a design in the competition for a new fighter aircraft for the "Luftwaffe".