I wouldn't have thought of this as being roasted suckling pig, as per the translation of cochinita pibil. Rick says that this is only an approximation anyway. We didn't roast anything, it was slow cooked; it wasn't a whole pig, just a shoulder; and it wasn't between 2 and 6 weeks old, I didn't check its birth certificate but I know that it spent 6 weeks at least in the freezer.
The complicated recipe is
here while the easy recipe can be found in Mexican Everyday. Break out your favourite citrus juicer and don't get any pulp in your eye.