Remove the protective cover with a 10mm socket, then loosen the castellated nut. As it is a low profile nut be sure the socket is pushed fully home.

 

When the nut is loose, remove it and put it on backwards to protect the threads of the ball joint, we are not too bothered about this here as we are replacing the old joint so it doesn't matter if the old one gets damaged.

 

Use a ball joint splitter to force the joint free, you could use a cheaper fork type here that you hit with a hammer - these normally damage the rubber boot on the ball joint, which is again not a concern as we are replacing the whole arm.

 

Although you can remove the top arm from the body and work on it at your own level I prefer to crack the two bush bolts on the body as it gives you something to lever against because they can be stubborn. Use spanners as shown to release the nut on one side....

 

....then the other side.

 

Un-bolt the bush assembly from the body, it should now drop out.

 

Drop it down and twist it round out from the back of the damper assembly - you do not need to remove the damper assembly at any stage of this process.