Installation:
The model files get into:
Update/x64/dlcpacks/patchday3ng/dlc.rpf/x64/levels/gta5/vehicles.rpf
(DELETE the original lazer+hi.ytd file)
And the vehicle.meta gets into:
update/update.rpf/common/data/levels/gta5
If you already have a custom vehicles.meta, then replace the Lazer entry with this: