Place the chicken in a container large enough to hold all the pieces (I used an extra-large zip-loc bag).
Combine the garlic, sour orange juice, salt, vinegar, pepper, oregano and cumin in a small bowl. pour the marinade evenly over the chicken; cover the chicken (or close bag and smush it around); refrigerate at least 1 hour or overnight.
Heat oven to 450°. Arrange chicken in one layer in a roasting pan; pour the marinade evenly over the top of the chicken.
Roast the chicken in the lower third of the oven, stirring during the last 10 minutes to coat with the sauce, until it is cooked through and the sauce begins to caramelize, 45 minutes to 1 hour.
Remove the chicken to a platter, spoon garlic sauce over the pieces.