Install:

Single Player:
Using OpenIV
-Copy zr350sa folder in mods\update\x64\dlcpacks
-Add: dlcpacks:\zr350sa\ to the file dlclist.xml in mods\update\update.rpf\common\data
-Spawn name: zr350sa

Fivem

Copy folder zr350sa inside 'fivem' to your server resources folder, add 'start zr350sa' to your server.cfg
spaw name: zr350sa