During the Warring States Period, how did Qin destroy South Korea?

In 236 BC, the king of Qin led Zhao to attack the emptiness of Yan State, and divided his troops to attack Zhao in two ways, which opened the prelude to the unified war. After several years of continuous attacks on Zhao, Qin greatly weakened Zhao's strength, but was unable to destroy Zhao for a while, so he turned to South Korea.

In 23 1 year BC, Qin Jun captured Nanyang. The following year, Shi Teng led the army to the north, captured Yangzhai, the capital of South Korea (now Yuzhou City, Henan Province), captured Wang Han 'an, set up Yingchuan County in South Korea, and South Korea perished.