Turn duck upside-down and prick through the skin into the fat all over the bottom of the duck so the fat will drain. Preheat oven to 35 degrees F. Bake the duck in a little water around 3 minutes. (Grab a leg; if it moves, it is tender enough.) Keep duck covered with foil, but baste often.
Make the glaze of equal parts marmalade and orange juice concentrate, thawed. Can add a little sugar to make it stick better; glaze is prettier if you add about 1 tb. cornstarch dissolved in a little water