Elsewhere,
If you're not in a survival situation, I would urge you to "live and let live." The opossum isn't threatening you in any way, and as others have pointed out, it may not be the culprit in your lawn destruction. Did you actually see him digging?
If you feel you must yield to your hankerin' for opossum or your blood lust, I will mention that the first step in cooking your opossum is cleaning it - skinning it and gutting it. Do you know how to do this? If you don't skin it and gut it, it will taste different than it should. You can tan the skin and make a fashion statement with it - maybe wear it as a hat or something. Daniel Boone had his coon-skin hat.
But I would plead for the little guy's life. He may save your life someday in return. OK, probably not, not who knows, maybe there's a one in a billion chance that he would, and he would do it proudly and compassionately, perhaps. Maybe. But if he's dead and cooked he'll never have the chance, and you will be doomed, calling out for opossum salvation that never arrives.