Changing front wheel bearing parts on many cars can be a fairly straight forward job but changing the bearing parts on an XK8 and XKR can be challenging and a special tool will be required to do the job.
There is nothing complex about the XK8 wheel bearing as such as they are a standard one piece bearing together with 2 circlips that retain the bearing in the housing.
The XK8 and XKR bearings are not noted for their longevity with car mileages between 30000 and 40000 miles typically requiring front wheel bearing parts changes.
Indicative signs of worn wheel bearings are the constant drone of the bearings which get worse if you turn the steering wheel and generally the rough feel when driving the car.
At the first signs of a worn wheel bearing, they should be changed as soon as possible to avoid additional work (and costs) in the future.
One of the first problems to be encountered is the removal of the bottom ball joint which will be tight and often has to be cut off.
Removal of the calliper and disc is usually straightforward.
However, removal of the ABS rotor nut is required and this requires a special tool (rotor nut socket) to undo it without causing expensive damage.
The rotor nut has a series of castellations on it for the wheel speed sensor to pick up.
The sensor has to be removed which is also expensive if damaged.
With the hub off the car and suitably retained in a vice, the next challenge is to remove the rotor nut which requires considerable force requiring a very large torsion bar lever to move it.
Once the nut is undone, two special circlips need to be removed and then the bearing has to be pressed out of it's housing.
A hydraulic press is best for this and ideally a cradle to secure it.
Best use you local auto engineer / garage for help here.
Refitting is the reverse of the above, but hopefully now you will have a much quieter XK8 / XKR and overall improved driving feel.