First, you have to prepare the Achiote Paste. This is used to marinate the pork. First, put the Annatto Powder, Ground Cumin, Black Pepper, All-Spice seeds and whole cloves into a spice grinder. Grind into a fine dust. You wanna do that because if you don't, the dust can be VERY gritty. Not good. Cut up the habanero peppers. I use three. I also leave the seeds in and most of the membrane. USE GLOVES WHEN HANDLING AND CUTTING UP THE PEPPERS. I cannot stress that enough. If you use your hands to cut the peppers and then touch the seeds and membrane and then touch or scratch your face or eyes or any bit of your skin for any reason, you're gonna be the sorriest person on the planet. Also, take the time to cut up and mince your garlic. You can use your hands to do this. Pour in your orange juice, white vinegar, minced-up habanero, add your grinded up spices (if you used a blender to grind up your spices instead of a grinder, you don't have to do this), salt and garlic and then blend well for about a minute. If you think you still have some grit or pulp from your ingredients, keep blending. After it's well-mixed, pour in a full cup of lemon juice. I like to just buy the stuff, pre-squeezed. They DO sell all-natural stuff, so you won't be cheating too much when you squeeze it from a bottle. After that, add in 2 to 3 shots of tequila. Blend again. Get your pork shoulder and cut it into 1 to 1 1/2-inch cubes. Once done, throw all the cut-up meat into a big 1 1/2-gallon Ziploc bag. Pour the Achiote Paste you've prepared into the bag with the chopped-up pork and MAKE SURE THE BAG IS SEALED. This juice, when it drips, is capable of staining and leaves a pungent smell due to all the acids contained in it. Once sealed, put it into the fridge and let it marinate overnight. If you don't want to wait, allow two hours to marinate. Next, preheat the oven to 325 degrees. Once properly marinated, get your casserole or baking dish and line it with aluminum foil. I recommend using the wider yield because this helps prevent spillage into the dish. Once the pan is lined and you have slack foil on the sides, pour in all the pork and juice and close the foil up over the meat. It wouldn't hurt to add ANOTHER layer of foil and tuck the meat in on the inside of the pan. This prevents any steam from escaping, thus properly allowing the food to slow cook perfectly. Then, add one more piece on top to go AROUND the outside edges of the pan. Once the oven is ready, put the entire dish in (make sure to handle it carefully; you don't want it to slip and fall) and shut the door. Set the oven timer for 4 hours and don't look back. The meat slow-cooks on its own and you DON'T need to check on it. Doing so makes the oven lose heat. During the last 30 or so minutes of the cooking, prepare your rice according to the package. CAREFULLY, remove the dish from the oven after the timer has gone off and CAREFULLY, open up the foil, avoiding ANY escaping steam. Use a fork to break up the steamed pork into shreds. This allows the meat to absorb a lot of the left-over juice. This also allows the pleasant side-effect of the pork tasting even BETTER the next hour and even the next day. If you want to get fancy and act like you own a swank restaurant, get a large lettuce leaf and then spoon out an even bed of rice on top of it. If you don't feel like using lettuce, just spoon out a bed of rice on a plate. Spoon out a generous amount of pork on top of the rice. Garnish with a jalapeno pepper -- and enjoy. :).