Go to the official WickedWhims website
Find the download page for the latest version
Choose the correct file for your game version and platform
Download the file to your device
Extract the downloaded archive if needed
Open the extracted folder
Copy the mod files into your Sims 4 Mods folder
Enable Mods and Script Mods in The Sims 4 settings
Restart the game
Verify the mod is working after launch