Instructions
Open the Angry Birds game and point it to World 5, which is called "Ham 'Em High."
Go to the second group of levels, which is labeled as number 13 at the bottom of your Angry Birds screen. Tap level 13-12 to open it. Note that you must have successfully completed every level leading up to 13-12 before it will become unlocked for play.
Sling the first yellow bird anywhere to get rid of it. Sling the second bird, a white bird, backward. Birds are shot backward by extending the slingshot toward the right and releasing.
Wait for the bird to fly over the hill behind the slingshot and then tap the screen to release the bird's egg. Try to drop the egg about halfway down the hill. The golden football egg will appear in the middle of your screen.
Go back to the Angry Birds main menu and select the "Golden Eggs" world. Tap once on the golden football to open the new level associated with it.