Rodney, the badge is attached the same as all the other Holden badges. It has two pins that push into the round keeper clips, you should be able to gently lever it off with a small screwdriver a little at a time from each side.

I normally spray a little CRC or lanolin spray around them so they slide out a little easier. If you can't get it off or don't want to attempt levering it off then cover it with a couple of layers of duct tape to protect it from the soda blasting.