Cant find out how to add a vehicle addon(looks like im missing files?)

Hello,

I have been trying to mod FiveM Story mod for a little while now but I cant seem to find any tutorial that works for me.

What I got is a vehicle addon which i want to add to FiveM but all tutorials i see tell me to add it to the dlcpack list and edit the dlclist.xml I do understand all that but I just dont have these files/folders.
They say I can find them in the citizen folder/common but all there is is UI data?

So bassically how do I make that folder structure?
If I have to what files do I copy to where?

Or is it just like adding mods to gtav it self by copying the update.rpf into the mods folder and such?

No one?