Pour marinade over the chicken legs in the zip top bag. Remove as much air as possible from the bag and seal. Turn the bag from side to side to make sure all chicken has been coated with the marinade.
Mix together salt, pepper, paprika, cumin, and cayenne pepper and add to olive oil. Add garlic, onions, and parsley. Mix together well with a fork. Slowly add beer as it will cause the mixture to foam and bubble slightly.