The best way I can think of is to delete it and while deleting, you're asked if you want to keep or remove from gamecenter, select remove from gamecenter. You're progress and cloud synching is done over gamecenter rather than iCloud so once its gone from gamecenter, its gone. Can't remember if there is a restore purchases option, I'm sure there is, but its worth being cautious on this point depending on whether you've purchased the extra maps or not. But just keep in mind, once you have removed from gamecenter, everything is gone and you will be starting from day one. I know that's what you personally are looking for, I'm more making that point for others. I'll check the restore purchases option and get back. Edit. Checked and can't find a restore purchase option. But as far as I know if you have already bought the expansion pack, you can simply select to buy it again and you wouldn't be charged as you've already payed for it. Bear in mind I didn't do this with this game but I have done it many times before with others that had dlc expansion packs and that's how it worked for me. On the off chance that you do get charged again, possible but very unlikely, just report problem in purchase history and Apple will happily refund you. I don't see this happening but just in case. Oh and another way to start over is to create a new gamecenter account. That new account will be created as a new profile in the game and will have no progress so it will do what you want as well. But it will also allow you to keep your other profile if you decided not to remove it from gamecenter.