Converting a GST 7.7 to brushless. Help?

So, throttle servo and ESC in the Y harness to the throttle channel then?

And by the way, do you know how to grind a flat spot on the motor rotor? Or the easiest way? Thought about simply closing up the holes on the motor with lots of tape and stuff to prevent anything from entering the holes, and just do it manually. It doesn't need to be that deep.