As far as I know, the ball joints are the originals. That is, they have never been replaced as long as I've owned the car, which is over four years and 45,000 miles.
So how difficult is it to replace the ball joints? Is it a DIY job, or are a press and special tools needed? Also, if it is a DIY job, what else should be replaced, for preventative reasons, while I'm in there?