This is the ball joint tool I use:

That won't work for removing the lower ball joint out of the upright.

Yeah that tool is no good for the lower ball joint removal as its pressed into the knuckle of the wheel hub. This might be useful as a press to install the new ball joint but as I say, if you clean all the rust out of the knuckle, PB/WD40 the heck out of it, then copper grease/anti seize compound all around the top of the ball joint not forgetting the lugs where the torx go through then when you need to get them out again, should be okay. Now the reason I do all this prep is that I installed mine 18 months ago and now I have a Powerflex bush kit to install on the control arm. So I bought some new Lemforder ball joints as they are on sale at Euros and the likelyhood of me splitting the boot on the ball joints when I remove the existing is hight. For £70 bucks I can fit new ones for peace of mind I get new parts in and don't have to worry about being really careful. I will update you all at the weekend if all my prep to make the ball joint easy to come out works for if its a total SOB again.

Right, ball joints out with a bit of a fight at the weekend. Not nearly as bad as before, no cutting required but I did have to hit it with a BFH about 50 times. so... Unscrew torx bolts which secure them on to the knuckle, then used a blunt chisel on lugs, after about 5 mins of hammering it slowly began to rotate, then from above I used 20mm socket on a extender bar and pounded on it with BFH and it came free. The anti seize had done its job but still they are in there real tight. Also I fitted my Powerflex bushes and I can report they are very very good. Its stopped my clunking, although my bushes had gone and the steering is much more dampened and tight under breaking. It used to dart a bit left and right quickly. Now it is solid and comes to a stop with no vibration. I am very happy. I know that these are not cheap parts and you have to press the old ones out and the new kit is an easy assemble in, but its now done for life.

I just found two slide hammers look like in the attached pics. Wonder if they are good for pulling out the ball joint or which one is better?

I think #2 with the box would be good for the ball join in the knuckle. That is, if the hole in that box is big enough for the ball joint thread to go through

Thanks for the reply! Just checked that the diameter of the hole is 24mm. I think that the hole is too big as the nut size is just 22mm. Any solution?

A couple of big washers to prevent the nut from going through the hole. Washers have to be thick enough to absorb some of the poundings from the slide hammer.

The slide hammer might work. The BMW dealer tool is a slide hammer with an end that screws on the ball joint. I couldn't find a generic one that fit. The box looks like it might with the washer idea. Keep us posted!

On my 2005 4.4, both ball joints (never replaced before) came out easily (without using any special tools) after thoroughly spraying liquid wrench all around the ball joints a day earlier and a couple of hours before attempting to remove them. The driver side popped off just by tugging side to side the still connected arm. The passenger side required two light blows on a screw drive placed on top of the ball joint and it popped off right away. Leave the arm still connected to provide leverage.

As a couple of others have pointed out, I would say the critical factor is to apply liquid wrench well in advance of the project. The ball joints were rusted on and thus I think it would have been extremely difficult to remove them without thorough lubrication. You have to give ample time for the liquid wrench to seep through the joint. I was surprised how easy they were to remove.