The Sims 3 Discussion
The launcher should automatically find it and ask you to install it.
You can find it for download by googling the version you want, but I found that the specific patch I wanted--no matter where I downloaded it from--had a region error and wouldn't install; so I ended up having to give up most of the mods I used by going to the newest patch through the launcher.
* Updated game trainers and cheats daily
* Get notified when new cheats are added
* Request which games get new trainers
* Priority support with any problem
• 9999999 Lifetime Rewards
• Needs Always Full