The Ming Dynasty Militia

In the seventeenth year of the Tianqi era in a parallel world, Li Xiang transmigrates from modern society to the Ming dynasty. Armed with knowledge from several centuries in the future, he builds guns and cannons, using steel and fire to save the suffering masses of the last Han Chinese dynasty, and uses ideas from the future to arm the people's minds. (The author isn't a historian, so please point out any mistakes. For details that can't be changed, please treat this as a parallel-world story rather than historical fiction. Many thanks.)