First Download and install Custo's Police Heli Pilot Mod: https://www.gta5-mods.com/player/police-heli-pilot-lspd-sahp

Once that has been completed, install my provided files into the following locations: 

Peds: Grand Theft Auto V\update\x64\dlcpacks\mpheist\dlc.rpf\x64\models\cdimages\mpheist_componentpeds.rpf

Pedprops: Grand Theft Auto V\update\x64\dlcpacks\mpheist\dlc.rpf\x64\models\cdimages\mpheist_componentpeds_p.rpf