How to clear/reset app data?

I am trying to reset the data in the app Crime City, as i am trying to set up a new character on my itouch. lol don't worry- it is an older model with a lot of cracks in the screen so I really don't use it for anything else.

I delete the app then reinstall it- same data. I then restore my ipod without a backup, and then reinstall the app- same data. What does it take to reset or clear the app data/memory stored in my itouch? Thanks