Default How Do I Make My S5 into chinese?

Hey, I'm trying to change the language of my s5 to chinese but its not in the options. So, I tried flashing the firmware of the chinese version of the s5 but it did not work. So I was wondering if there was another way to put a chinese firmware on my T-mobile s5 or change it to chinese without using morelocale 2 or any other similar apps because most of it is still left in english. Thanks!