Instructions
Open The Sims 3. Click "Edit Town" in the bottom left corner of the screen.
Click "Save" or "Continue." It doesn't matter which. Click the specific game material you want to upload.
Click "Share." Choose to save either the household or the household along with all items inside based on what you want to upload.
Enter a name and description for the game material you want to upload. Click on the "Check Mark."
Wait a moment while your game material exports. The game will indicate when this process is complete.
Exit the game and go to the Launcher. Click "Uploads," click on the box next to your desired game material and click "Upload" to finish your Sims 3 upload.