how do you remove the rear bumper? I need to replaced only the facia

There should be bolts to the rear bumper visible from underneath the vehicle. There may also be screws holding the fascia/bumper to the rear wheel well inside the well -- also visible. As far as hidden fasteners, there are usually some underneath the button-type covers these vehicles have in the rear bumper fascia. You may find it useful to remove these covers and check for fasteners. Wiring-wise, I don't think you have to do anything, although you may need to remove the lights just to make sure the taillight wiring is not clipped to the bumper assembly.