The Golden Eggsteroid is hidden in the bushes on the west side of the planet in level 3-10, though you can see it shining. Softly launch any bird down the hill behind the slingshot to obtain the Eggsteroid. Once you hit the egg you'll immediately be transported via a wormhole to the level.
It's hard to pop directly the pig because he's bouncing.
Hit the Super Red Bird at the piece of ground above so it can hit the Moustache Pig, awarding you with 20,000 points of the leftover birds.
You can never get more than 25,000 points because you get only 5,000 points for pop the pig.