How do you do a clean install of Stuffit?

Ok I updated my stuffit for sims3 and made a mistake of updating and I deleted the app and even used appzapper, and when I install the RIGHT stuffit, it asks me to delete the older versions and I do, but sims launcher still doesn't work, I think this might be MY problem and the reason its not working...

All you have to do is download the version recommended, then install it. Then you can just simply right click the .rar file, go to open with and then locate / select the older version of stuffit.