Simply unzip and place the folder "Portraits" in C:\Users\yourUsername\AppData\LocalLow\Owlcat Games\Pathfinder Wrath Of The Righteous

Unzip and place the folders "Lann" and "Daeran" in C:\Users\yourUsername\AppData\LocalLow\Owlcat Games\Pathfinder Wrath Of The Righteous\Portraits.
If you don't have Custom Npc Portraits, it means you'll have to change portraits manually.