Complex sentence: Michael D. Lumpkin was appointed as Principal Deputy Assistant Secretary for Special Operations/Low Intensity Conflict on April 25,2011, and replaced by Michael A. Sheehan on 1 November 2011.
Split into simpler sentences: Michael D. Lumpkin was appointed as Principal Deputy Assistant Secretary for Special Operations/Low Intensity Conflict on April 25,2011. On November 1,2011, he was replaced by Michael A. Sheehan on 1 November 2011.