Unzip the downloaded file and place all those files into your Sims 4 Tray folder, which can be found at
Documents » Electronic Arts » The Sims 4 » Tray.

Don’t forget to download all the custom content listed. Otherwise, your sim won’t look like mine.

Place custom content files into the Mods folder located at
Documents » Electronic Arts » The Sims 4 » Mods.

Tutorial: How To Download My Sims From The Gallery 

Custom Content used:

Poses: https://katverse.com/category/custom-content/poses/

CAS Background: https://modthesims.info/d/639065/old-school-cas-room.html

Sliders and presets

Other CC

Author Katverse