How do you corrupt an egg on gpxplus

You find a cor. orb or buy one in the backroom Easy

Edit: No. This person asked HOW to corrupt an Egg on Gpxplus. Not how to get a Corruption Orb. You corrupt an Egg by using it on one of these Egg's: Bidofo Egg, Groudon Egg, Lugia Egg, and Dialga Egg.