Complex sentence: However, the Goryeo Dynasty of Korea printed Jikgi by using the similar method about 72 years earlier than Gutenberg, and Jikgi is the world's first press-printing material that is extant.
Split into simpler sentences: However, the Goreu Dynasty of Korea printed Jikgi by using this similar method. Korea made Jikgi about 72 years earlier than Gutenberg which made Jikgi the world's first press-printing material that is extant.