From the main menu, tap on the Wardrobe icon. This will display a list of the Costumes you own.
To change Costumes, open the Wardrobe and just tap the Costume you want to wear and tap the "Equip" button. A Costume must be unlocked before you can wear it.
To change Costumes, open the Wardrobe and just tap the Costume you want to wear and tap the "Equip" button. A Costume must be unlocked before you can wear it.
For more information, check out: <How can I unlock and upgrade Costumes?>