Rinse and dry meat well with a clean towel.
Place pork, skin-side down, on a large rimmed sheet pan and poke deep, 1-inch holes, throughout the meat and in the fatty layer with a paring knife, being careful not to pierce the skin; you can’t have too many holes.
Pour adobo over meat, in batches, using your fingers to push adobo deep into the meat.
If you’re worried about your hands smelling like garlic, which they will, wear plastic gloves.
Set out a long sheet of plastic wrap, layering with subsequent sheets, as needed, to ensure you can securely wrap the entire pork shoulder.
Transfer pork to plastic wrap and wrap tightly, adding sheets of plastic, as needed, to ensure pork is completely airtight and juices are contained.
Set on a rimmed baking sheet, or disposable aluminum foil pan, in case it leaks.
Let marinate in the fridge overnight, if possible, or at least least 2 to 3 hours.
Once the pork has marinated, pre-heat oven to 400°F.
Working over the sink, carefully remove pork from plastic wrap, discarding any remaining adobo.
Place the marinated pork shoulder, skin-side up in a deep roasting pan, and wipe the skin with a clean cloth.
Rub skin with 1 teaspoon salt.
Loosely tent foil over the pork shoulder, spraying the foil with cooking spray or brushing with oil in any areas that may touch the skin, as it will stick.
Place on center rack in pre-heated oven.
Roast in the oven for 1 hour; remove from oven and carefully remove the foil and rotate the pan.
Return to oven and continue roasting for another 2 to 3 hours; rotating every hour or so, and watching closely.
Add water to the pan, as needed, when juices evaporate.
The meat is done cooking when the juices run clear and the thickest part of the shoulder registers 160°F with a meat thermometer.
The skin may take more time to crisp, but watch closely so that it does not burn.
Tap the top of the skin with the back of a knife or metal spatula, and listen for a decidedly hollow sound.
Remove from the oven and let rest for 10 to 15 minutes; transfer to a large cutting board.
If desired, remove the skin from the roast by slicing it along the underside of the bone with a long, sharp, slender knife; run the knife underneath the skin starting from the bottom until loosened, then lift the skin from the meat.
Rest kitchen shears in the warm oven until ready to slice pork.
Trim excess fat from the meat, if desired, and slice in large chunks or slices, to serve.