The Closed Guard is an awesome position to first of all defend yourself from the bottom and second to mount an offense. But when you don't want to be on the bottom you need to either sweep your opponent to gain the top position or stand up.
In the video above UFC Welterweight champ George St. Pierre demonstrates a very solid way to stand up from the guard.
As you would expect from GSP he is very technical and does a great job of explaining the details. I really like the way that he uses leverage with the shoulder pressure to allow him to stand.
