Install:

Single Player:
Using OpenIV
-Copy elisegt1 folder in mods\update\x64\dlcpacks
-Add: dlcpacks:\elisegt1\ to the file dlclist.xml in mods\update\update.rpf\common\data
-Spawn name: elisegt1

Fivem

Copy folder elisegt1 inside 'fivem' to your server resources folder, add 'start elisegt1' to your server.cfg
spaw name: elisegt1