Best course of action... but to be on the safe side you need to get rid of your save paths as well... You don't necessarily need to restart from the beginning... delete all files that come from the " extra content " download a virgin version create a new game file at the very beginning and if someone feels generous they might give you a save file to swap so it land you where you are at !
It did it's work already... I knew it had to be something like this...
A word of advice for the future : don't use these tools in the future ( don't even download them ! ) and stay away from the CAT save files since they are pre-cheated as well...