This mod works using the "AddonPeds" script. If you don't have it already installed please download it from here:
https://www.gta5-mods.com/scripts/addonpeds-asi-pedselector

After you have installed it, place all the files in this path:
mods/update/x64/dlcpacks/addonpeds/dlc.rpf/peds.rpf
(You'll need OpenIV for this.)

Then just add the ped using the "AddonPeds Editor.exe" that came with the AddonPeds script, and rebuild everything.