You can't You would have to redo the whole mod from scratch, in this case even the 3D model won't be compatible, so it's not possible
aww --- Post updated --- but someone made a tank out of a GTA V mod, how did he do it? Spoiler: Picture
I have never seen this as a BeamNG mod in my life, but I guess they just stole someone else's tank mod and only replaced the 3D model with the one from GTA
The most important part of what you are asking is missing, what or where is this mod actually from? Is there a program or app that can even extract the data from the format inside the zip file?
To be honest, your probably be better off getting automation game and making new car mods that way. It's literally the quickest way to get custom (specific) vehicles into beamng. With a bit of work you can even make interiors for cars now.