Complex sentence: In May 1984 Nar Bahadur Bhandari's government was dismissed by then Governor J.H. Taleyarkhan thereafter Mr. Gurung was sworned as the third Chief Minister of Sikkim for 13 days.
Split into simpler sentences: In May 1984, Nar Bahadur Bhandari's government was dismissed by then-governor J.H. Taleyarkhan. Shortly thereafter, Gurung was sworn in as the third Chief Minister of Sikkim for 13 days.