How do I replace cars in GTA V [PS4]?

I tried it on my PC, and with Open IV you have the option between Windows, xBox 360 and PS 4. But how exactly do I do that now? I only find instructions for such a mod menu.

You can't use mods on the PS4.

Do you want to modd on ps4? For this you would have to start with the Ps4 jailbreak, which is still not possible (or nothing has been published yet). Or did I misunderstand the question?