Q: In otherwords, how can I do it and what tools will I need? :) cheers
A: You will need: 13,16,17,18,19mm spanners and sockets (preferably 1/2" drive). A big bar/lever a short extension bar for your 1/2" sockets a BIG hammer or hydraulic press (capable of 10 tonne) wire brush WD40 or similar. Jack and axle stand. I will give instructions for O/S wheel for ease of reference, but both sides are done exactly the same. Jack up O/S/F wheel and support the car on axle stands. Remove the wheel. There is a bolt that connects the ball joint to the bottom of the hub. Usually a 17mm bolt head and a 16 or 17mm nut on the other side. Remove this bolt and nut. Insert your big bar from the front of the car, over the lower arm and under the floor of the footwell and lever the ball joint out of the hub. (it may be tight, get someone to stand on the end of the bar and then hit the bar with a big hammer) Now moving to the inner end of the lower arm. There are 2 bushes holding the arm to the subframe. Remove the bolt holding the front bush in place, usually an 18mm head. Sometimes the nut on the other end is caged sometimes it isn't and sometimes it is meant to be but has rusted off. Now remove the bolts holding the rear d-bush to the subframe. These go up through the subframe and bush from underneath. One is 13mm and the other is 16,17,18 or 19mm (i can't quite remember which!) Remove the complete lower arm, which may take a bit of wiggling to get it out. Now it is time to replace the actual ball joint. If you have access to a press then use it to press the old joint out and the new one in, otherwise roll up your sleeves and use a big hammer. These joints usually press out with 5 tonnes of force, so you might not get it out using a hammer, it all depends how strong you are. Press the new joint in using a socket on the edge of the joint so that the force doesn't damage the joint. Now refit the arm in the reverse order that you took it out in. When refitting the ball joint into the hub ALWAYS fit a new nut and bolt as they are high tensile bolts. This will probably take you quite a while to do depending what state the nuts and bolts are in. I would recommend taking it to a garage to do as they should have the job done in less than 1 1/2 hours. EDIT Trevor's additions are quite correct. I have seen someone hammer the ball joint out of the arm, and the arm doesn't break providing it is properly supported in a vice. However, the man that did that is an OX of a guy! I doubt that i would be strong enough to do it. The press would certainly be a safer more professional option.