Complex sentence: The election will only be for the remainder of his term until 5 February 2018, not for a full nine-year term; whoever is elected will be allowed to stand for reelection for another nine-year term.
Split into simpler sentences: The election will only be for the remainder of his term until 5 February, 2018. Whoever is elected will be allowed to stand for reelection for another nine-year term.