how labor intensive is a bearing replacement on this vehicle.
In my opinion, its a pain in the dairy air. Several specialty tools/pullers not to mention an alignment will be needed. Unless your familiar working on the Taurus/Sable suspension and steering systems, trust me, its a pain.
My opinion on replacing a ball joint in one of these cars, its worse than replacing the wheel bearing. Instead of the ball joint being pressed into the lower control arm, its pressed into the knuckle. Also the standard bearing press that you can buy or rent from the local parts stores will not work. The sleeves included with the press are not deep enough. Found out the hard way.
Chip is right, do not use a pickle fork to disconnect the tie rod and the ball joint, you will destroy the boots. A pitman arm puller works very well. Also be careful with the stabilizer bar link, the original on my Taurus was made of plastic.