Funnily enough, I just did the job yesterday, here in cold and wet Britain.

Stuart, you need a ball joint splitter to release the taper fit of the steering idler into the steering relay (that bar of metal that goes across the vehicle and causes the two front wheels to steer in sync). The Pitman arm is the lever that comes from the steering box and moves the steering relay left and right.

If you don't have a ball joint splitter, you will have to come up with some arrangement that applies upward pressure on the threaded end of the idler that pokes out under the steering relay after you have removed the split pin and nut. Sometimes you can arrange a 2 leg bearing puller with its legs over the top of the steering relay and the threaded part of the puller bearing on the bottom end of the idler.

Be warned that the pressure required to get the taper to come undone is pretty substantial .... up to a ton may be required, so the best way to do the job is to get a ball joint splitter. I have had bitter experience of struggling with makeshift arrangements that slip off, just as I have beeen increasing the tension!

There is another evil way of doing the job which involves supporting the relay arm against the chassis, jacking up the vehicle, putting an axle stand below the bottom end of the idler and, using the jack, dropping the vehicle down on the end of the idler taper. It has all sorts of nasty consequences if something goes wrong, so avoid doing it this way if at all possible !

At least you will be warm while doing the job, down there in Oz.