The question as written is unclear. Please see the below questions that answer the possible interpretations of the question.
The North Korean leaders make declarations by fiat. They are dictators.
The North Korean regime was established by the Soviet Union as part of their efforts to expand the communist bloc.
The internal structure of North Korean politics is not very understood. The Supreme Leader comes to power dynastically, e.g. when a Supreme Leader dies, his son succeeds him. However, there is a large amount of power wielded by the generals in the North Korean Army and there are likely some bureaucrats who also wield power. Some of their ascension may be meritocratic, e.g. they rise because they do their job well, some may be nepotistic, e.g. they rise because of who they are related to or are friends to, and some may be cronyist, e.g. they rise as a favor from one influential group to another.
Most dictators abuse power, such as:HitlerMussiliniStalinSaddam HusseinNorth Korean leaders - son just inherited leadershipCastro
Lack of sufficent air power.
He born into North Korean Kim Famiry!
Rebels.
As in all wars since 1914 air power is the main controlling factor. It was the UN control of the air, (mainly US), which made it impossible for the Chinese and North Korean armies to have air support. If your enemy has air support and you don't, then you are not going to win.
With the exception of Chile, all communist leaders have used force of arms to take control of a country.
North Korea has been a communist government since its establishment in 1948. Following the end of World War II, the Korean Peninsula was divided along the 38th parallel, with the North becoming a Soviet-backed communist state under Kim Il-sung. The Korean War (1950-1953) solidified this regime, which has remained in power ever since, maintaining a strong emphasis on Marxist-Leninist principles and a personality cult around its leaders.
It appears to be without civil unrest but it is a dynasty -- each leader is the son of the previous leader. If you are asking if there's a way outside agents could change a current leader, not without war.
An example of an authoritarian leader is North Korean leader Kim Jong-un. He exercises absolute control over the country, suppresses dissent, and maintains power through a cult of personality and a tightly controlled state apparatus.