Pat dry the ribs and shoulder with paper towels. Cut both into large pieces, ribs into 3-4 segments and shoulder into similar-sized pieces, to fit your pot comfortably.

Create an herb bundle by placing oregano, peppercorns, cloves, thyme, and bay leaves in the center of a medium-sized cheesecloth square. Tie the top with kitchen twine to secure the herbs and spices. 

Place the cazo over medium to medium-high heat and melt the lard. Once it reaches 325°F, brown the meat in batches, flipping as needed, until evenly browned - about 30 minutes per batch.

Dissolve the salt in the hot water.

Reduce the heat to medium-low. Add all the browned meat back to the pot, along with the herb sachet, onion, garlic and salt solution. Simmer gently for 45 minutes, or until the meat starts to tenderize, adjusting the heat as needed to maintain a steady temperature.

Soak the skin in a large bowl of water with 1 TBSP of dissolved salt for 30 minutes to soften and clean it further. After soaking, remove the skin from the water, pat it dry with paper towels to remove excess moisture. 

Once the carnitas have started to tenderize (30-45 minutes before reaching fork tenderness), lay the pork skin on top, ensuring it's completely submerged in the fat.

Once the meat and cueritos are tender and cooked through, carefully transfer them to a sheet pan with a rack to drain excess fat. Let them rest for 10 minutes before dicing the cueritos and chopping the carnitas. 

Then, assemble the tacos by topping the carnitas with diced cueritos, cilantro, onion, a squeeze of lime juice, and a spoonful of salsa taquera.