If its making a clicking noise especially when cornering it will be the outer one. If its the n/s it might be easier to change the whole shaft, the o/s one probably has a centre bearing.

You will need to seperate the bottom balljoint after slackening the nut on the driveshaft for which you really need a 3/4" drive socket set, you should then be able to pull the hub away far enough for the end of the shaft to drop out. If you are just fitting the joint, they are normally held on by an internal spring clip, slide back the rubber boot, find the inside end of the joint where it sits on the shaft and give it a sharp knock outwards with a fairly heavy hammer, it takes quite a clout to compress the clip - this is all assuming that your car is the same as most other makes I have done.

Its not to difficult a job but messy!