It seems there are two methods to accomplish this; Joe Dante advocates that the right wrist hinges backwards while others discuss a slight roll of the forearm followed by an and down wrist c0ck. The first method results in what appears to be a closed club face at 3:00 while the second results in the toe up position. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.