Download the mod files from a trusted source
Extract the files if they are in a .zip, .rar, or .7z archive
Open the Sims 4 Mods folder
On Windows, go to Documents > Electronic Arts > The Sims 4 > Mods
On Mac, go to Documents > Electronic Arts > The Sims 4 > Mods
Place the mod files into the Mods folder
Keep script mods no more than one folder deep
Make sure script mods end in .ts4script
Make sure package files end in .package
Open The Sims 4
Go to Game Options
Open Other
Enable Custom Content and Mods
Enable Script Mods Allowed
Restart the game
Check the mod settings or content list in-game
Update mods after game patches
Remove outdated or broken mods if problems occur