I did a write up when I changed out my wheel bearings. If you are mech. inclined, you should not have much trouble. There are a few special tools, but with bearings that last in the 50-60k mile range, you will prob. be doing others in the future. You could allways get the tools and sell em to some one else that needs them and recoup most. of the cost.
Steve
http://boxster.wikia.com/wiki/Wheel_Bearing_Change