land cruiser trans oil change

thanks for your answer but just to make sure , first i should drain the trans from the bottom which only 40 or 50 % will be drained and i top up the new trans fluid and change the filter plus adding the transX to the recommended level right ? what is encouraging me to do it, that there's no sign of trans slipping its still holding nicely .

I would change the fluid, start the car and drive it a few miles and then drain and fill again before adding the TransX. This will get rid of most of the oxidized(brown) fluid.