how to make script for KOS to change name ingame??

Um...find the memory address of your name stored in the game and change it?

If your looking for a name its going to be stored as an array of chars or bytes. So you might be able to look in memory for your name in the data section if you can attach a debugger. Assuming you can't You may want to serach for the byte representation of your string. Keep this handy: ASCII Table So you will know they numeric value of each character.

Then you can just search for the numeric representation of your text and then just see what references it and you should be good to go. What references it should be the pointer to the char array.