Once the file is downloaded and unzipped you will see two folders, one called Tray and the other called Mods. Copy the content of both to the corresponding folders. (Documents/Electronic Arts/The Sims 4/Tray or Documents/Electronic Arts/The Sims 4/Mods). 

 

Don't create subfolders in mods, copy the folder as you see it to mods. If you already downloaded other sims from this site, overwrite folders and files to avoid duplicates.

Black girls on the beach (public content)