You don’t need 3DS Max or Zmodeller. You can use this in your own server using the same method as converting add-on vehicles.
TLDR: open dlc.rpf with a program like 7zip or OpenIV and get the files needed to stream this add-on and load the data files
https://github.com/mecwerks/fiverebornstuff/tree/master/addon-convert this README still applies except the last part you’d obviously start it through your server.cfg
also Simple tutorial on how to add vehicles to your FiveM server [Add-on/Replace]
and https://forum.cfx.re/search?q=add-on%20vehicles%20%23development%3Atutorials