Simplify the following text for a Grade 6 native English-speaking person.
Original: Kim Jong-nam ( Korean : ê ì ë , Hanja : é ` æ # ç '' ) ( born May 10 , 1971 ) , is the eldest son of Kim Jong-Il , ruler of the Democratic People 's Republic of Korea .
Simplified: Kim Jong-nam ( born May 10 , 1971 ) is the eldest son of Kim Jong-il , leader of North Korea .