erase city linked to FB account?

Thanks for your answer. I was able to unlink, delete the appdata and start over, but as soon as you re-link it, it says a game is already associated with this account, do you want to play that game?- with no option to overwrite your cloud game with the new one. As far as just selling off everything and starting with a blank board, The effect I was trying to achieve was to have a game at a lower XP level to circumvent the dismally implemented global trade system. Because of the diversity of items offered at the higher levels,(and the terrible lag between steps in the purchaseing process and lack of any locking system) I have not been able to successfully purchace a bulldozer blade since level 17.(i'm now close to 30)  I have found my solution, it is the hard one, and if youv'e followd me so far you can probably guess what i'm talking about although i'm not sure it's the kind of strategy that should be discussed here, so i'll just leave it at that, but thank you for the time and input.