Follow one of these Twitter accounts, and on their account page look for the hashtag that they mention:
@MiniSavesTheDay, @MiniHeroes1886,@SuperMiniHer0es, @AhhForce, @MiniHero37, and @BigvsMini.
For example, with @MiniSavesTheDay. Follow them, and tweet at them with the hashtag  #CokeMiniContest356 to get it. They’ll DM you if you were one of the first 2,500.
For @MiniHeroes1886F, follow and tweet at them with #CokeMiniContest11 to get it.
For @SuperMiniHer0es, follow and tweet at them with #CokeMiniContest73 to get it.
For @AhhForce , follow and tweet at them with #CokeMiniContest41 to get it.
For @MiniHero37, follow and tweet at them with #CokeMiniContest196 to get it.
For @BigvsMini., follow and tweet at them with #CokeMiniContest187 to get it.