How can I add Hexa H copter?

I want to add Hexa H type copter to arducopter…

Is there any samples or reference??

I don’t know which source code I edit…

Please guide me…

I guess you are going to build a H copter with 3 motors left and right, not 3 motors front and back.
With 3 motors on each side, it should fly as an Hexa in X config. The distinction between X and H is there to take frame flex into account, so the flex adds to the desired yaw direction and does not counter it.