Instructions
Create a free account on The Sims Resource by going to the account sign up page. After creating your account, check your email to activate your account and log in.
Go to the pacifier mod download page and click the green diamond icon to download the "sims3pack file."
Open the file by double-clicking on it. This will open the "Sims 3" launcher and the download will be installed automatically. Click the "Play" button to start "The Sims 3." The pacifier will appear in Create-A-Sim mode under "Accessories."