Instructions
Insert the memory card into one of the two memory slots on the front of the Xbox 360 console.
Click the "My Xbox" tab. Select "System Settings," then "Memory."
Find the memory card on the menu, then choose the type of content you want to delete. Select the data you want to delete, and choose "Delete" from the menu. Select "Yes" to confirm the deletion. Repeat for all the content you want to erase.