You can install most of this mod manually, but you will not get the full experience. I highly recommend using the .oiv file.

- Drop popgroups.ymt into mods/update/update.rpf/x64/levels/gta5.
- Drop popcycle.dat into mods/update/update.rpf/common/data/levels/gta5.
- Drop dispatch.meta into mods/update/update.rpf/common/data.
- Drop vehiclemodelsets.meta & loadouts.meta into mods/update/update.rpf/common/data/ai.
- Drop setelegen folder into mods/update/x64/dlcpacks.
- Add the line "<Item>dlcpacks:/setelegen/</Item>" into dlclist.xml in mods/update/update.rpf/common/data.
- Take all files from the Scenarios folder and drop them into mods\update\update.rpf\x64\levels\gta5\scenario.