Once you have a compatible PKG file, installation on a jailbroken PS4 follows these steps:

The PS3 used the complex , while the PS4 uses x86-64 architecture . Because of this, you cannot simply rename a .pkg file from one console and expect it to work on another. Most "conversions" you see online are either specific remasters (official) or emulated environments (unofficial). 2. How PS3 Games are Run on PS4 (Jailbroken Systems)

: A port of the PS3's PKGi, this tool allows jailbroken PS4 users to download and install package files directly on the console.