If you download the new update and delete the old one, there should be no problem running it. I myself have not found where the data is stored. However, it isn't important, if you hit a glitch between an old save and the new game...just start a new file...it doesn't take long to get back to where you were thankfully! That being said, I also havn't had an issue with an old save not running properly on the update. So ya, just delete the old folder, and replace it with the new. If it makes you feel more comfortable port the files from the new folder to the old and "replace" the similar files, then rename the folder. It should all work out just fine, either way.