Go back to ST entry, click on "Search our sweep" feature, type in "Miller Lite" and see if your t-shirt is listed as one of the prizes in any of those sweeps.
If you received an email that you won, email should specify how to claim prize.
If you purchased an item and received a winning notice, it should also specify how to claim prize.
Hope this helps. If not, come back, post again, and someone will try to help you.
And the Grinch, with his Grinch-feet ice cold in the snow, stood puzzling and puzzling, how could it be so? It came without ribbons. It came without tags. It came without packages, boxes or bags. And he puzzled and puzzled 'till his puzzler was sore. Then the Grinch thought of something he hadn't before. What if Christmas, he thought, doesn't come from a store. What if Christmas, perhaps, means a little bit more. - Dr. Seuss
May the Joy and the Meaning of the Christmas Season fill your hearts throughout the year.