I honestly hope your kidding. Leaving morals at the door, this idea is shit. First, how the hell do you plan to dig up and replace the dirt in a grave in one night!? With a backhoe it will take you several hours, plus police patrol cemetery's' after hours to make sure kids aren't "exploring" and this shit isn't happening. But hey, maybe your fucking a pro at digging. Now that you've uncovered your grave, obviously time to plunder correct!? Wrong, while some may bury their loved ones with expensive things the odds that some random persons grave has any are pretty thin. Lastly, let's say you've done some research and you manage to get the grave uncovered. If it were to be a fresh one, like your suggesting. As soon as you would open the coffin there would be a 99% chance of you vomiting from the sight and smell. Leaving DNA evidence and assuring you would be caught if you hadn't been in the hours of digging. Anyways best of luck.