Instructions
Turn on your PS3 game console and press the PS3 logo button on your controller then wait for the menu screen to appear.
Scroll right to "Games" and select "Game Data Utility." Scroll down to the "Little Big Planet" icon and press the "Triangle" button on your controller to bring up the options menu. Select "Delete" then "Yes" to confirm. The "Little Big Planet" game data is now deleted.
Insert your "Little Big Planet" game disc into the Blu-Ray slot of your PS3. Wait for the game to load and select "New Game" from the game menu screen to create a new profile.