Stab the pork shoulder in various places and insert the garlic pieces. Combine the adobo and sazon and use as a dry rub and coat pork shoulder. Rub the sofrito all around the pork shoulder. See the notes for preparing the skin.
Cover with plastic wrap and set in your refrigerator overnight.
Preheat your oven to 300° F. Remove the plastic from pork shoulder and place in a roaster pan.
Cook covered for about 5 hours. You can add ½ to 1 cup of water to the roaster to add some additional juices for later. The internal temperature should reach 205°F. The meat will be fall apart tender when it is done.
If you left the skin on, place the roast skin side up, pat the skin dry and turn up the oven temperature to 500°F. Roast uncovered until the skin is crispy on top to your liking. For extra crunchy skin use your broiler but keep an eye on it to be sure it does not burn.
Remove from oven, let it rest for 15 minutes and place half the shoulder on a large cutting board. Remove the skin and set aside. Discard the layer of fat.
Start chopping the meat with a sharp knife and place chopped pieces in a large bowl.
Take remaining juices from the cooking process and place in a container in the refrigerator to allow the fat to rise to the top and solidify. Remove solid fat and discard. If you have a gravy and fat separator, those work very well. Mix the juice with your chopped meat.
Portion off into individual containers and freeze. This will keep frozen for several months if you vacuum pack the frozen blocks from the containers.