Years ago someone gave my husband and I some venison. He cooked up a small batch and it was terrible, tough, gamey tasting. The rest of it lay in the freezer for months until the day he came home with a yard sale find, a book called How to Cook Game. The preparation and cooking method below turned the rest of that meat into some really tasty dinners.
Cooking strongly flavored game:
Brine it as you would a turkey. One cup Kosher salt to a gallon of water, or about 2/3 Morton Kosher salt or 1/2 cup table salt (no iodine). How long? It depends on the size of the piece of meat. For example, from a chart I found: pork loin 2-8 hours, whole pork loin 1-3 days. Get rid of the brine, rinse the meat.
Marinate it. Red wine is good. Apple cider works too. Add something acidic to help tenderize, orange or lemon slices, red wine or balsamic vinegar. Throw in an assortment of aromatics, onion, garlic, whole peppercorns, bay leaf, a blade of mace, juniper berries, sprigs of fresh thyme, a few splashes of Worcestershire sauce for example. I'd marinate for at least 6-12 hours, but don't leave it for toooo long or you'll just end up pickling the meat. Discard the marinade.
Cook as you would any piece of meat that might be tough. Brown and then pressure cook, braise (stovetop or oven), or use a slow cooker/crockpot. Be careful about adding salt or salty liquids like broth while cooking because the brined meat will need little or no more additional salt.