fog lights

Does anyone know how to go about changing the foglight on a G8? I have seen the assembly sketch but it looks like the only way is to take the whole undercount of the car off?

I desperately need a new fog light housing for my 2004 Bonneville GXP. I pulled up too far onto a parking space block and destroyed all the glass inside of it and really need another one so I can get my sexy new HID's in. I can't seem to find another one and i know that the gxp's have...