Ancient thread but people still find their way here, so if you don't want to mess around with registry stuff, just go into your game folder and you'll find a folder called "cloudsaves". In there is another folder that contains your saves. Copy the saves into a new folder (in the main game directory) called "saves", and the save editor should be able to find your saves (if not, tell it again where they are to make it re-check). When you're done, copy the edited save back to the "cloudsaves" folder and you're good to go.
Steam cloud might complain that the files don't match (or restore your unedited save) when you load up the game again, so either turn that off temporarily or edit a save with the game running and then load said save so that Steam cloud saves the new one when the game is closed.