Use this Mod Template to bring your own face into the simulator and/or change colors of the clothing.

Unzip the Folder "ZZZZ ...." into the community Folder. You can than actually change the name of this folder, but don´t touch the names of the files and folders within.
Navigate to  (MOD Foldername/SimOjects/Humans/Texture and open the respective Head file for your gender and phenotyp. You need software that can open dds files, for instance freeware like paint.net or gimp. The add your face/photo as a second layer and make the layer multiplicativ so you can arrange your face over the original. Then merge the layers and save the dds file (BC7 sRGB).

Use this video as a guide: https://www.youtube.com/watch?v=fHWEQq-loaY