Don't think this is a repost, i did some searching.
Grab a pen and a small piece of paper.
Go to your local Wal-Mart
Go pick up a Game Time Card
Walk around until ur in an area with low amount of camera vision and not any people.
Pocket the Card.
Go to the bathroom and go in a stall.
Write down the code on the small piece of paper.
Flush the toilet if there is someone else in there (lol)
Trash the card
Go home and play WoW.
Repeat in 2 months.
And yes, i have tried this. It is very simple.