The PlayStation Store
To find the Marvel costume packs, first access the PlayStation store. Sign in, then scroll down to "View All by Title" and press the "X" button on your controller. Pick the letter "L," then scroll through the titles until you find "LittleBigPlanet." Choose "Add-Ons," then "Add-Ons M-Z/#." From here you can find the Marvel costume packs for "LittleBigPlanet."
Costume Packs
As of October 2011, four Marvel costume packs are available for purchase in the PlayStation Store. The "LitleBigPlanet" Marvel Costume Pack 1 includes costumes of Iron Man, Thing, Daredevil, Doctor Octopus and Mystique. Marvel Costume Pack 2 has Thor, Spider-man, Elektra, Ghost Rider and Human Torch. In Marvel Costume Pack 3, you'll find Captain America, Wolverine, Invisible Woman, Venom and Rogue. Marvel Costume Pack 4 contains Hulk, Punisher, Green Goblin, Magneto and Storm.
Purchasing the Packs
Though you can download most of the costumes individually, the costume packs give you the best value. Individual costumes cost $1.99; the packs, which include five characters each, are only $5.99. Select the costume pack you want to buy and press "X." Select "Buy Now" from the menu that appears. If you do not have any money in your virtual wallet, you will be prompted to add funds from a credit card or a PlayStation Network Card. PlayStation Network Cards can be purchased at most retail locations that sell PlayStation 3 games. Add the appropriate funds and select "Confirm Purchase" to begin downloading the costumes.
Equipping the Costumes
After downloading the Costume Packs, exit the PlayStation Store and launch "LittleBigPlanet." After starting the game, press "Square" to open your Popit menu. Choose "Customize Character" and select the costume parts you want to use with the "X" button. Feel free to mix and match. You can scroll through the options with the left directional stick. By scrolling all the way to the right, you can find the "My Costumes" menu where you can save the costumes you've put together.