Hi, what you need to do is make 6 shinny areas around ring gear, oxy acet is better, you may do it with butane ? , it's obviously smaller than a car ring gear, go around and around with the heat, you will see the shiny areas changing colour's straw to blue-ish is ok, I haven't done a T160 ring gear, so that is the car method, I wouldn't bother with cooling the inner, set it up so that you can seat it with a 10mm punch if required, wear some leather welding gloves and drop it on. Cheers