If you are looking for general (not converting PS3 to PS4), the process is much simpler on modified consoles. Prepare USB: Format a high-capacity USB drive to exFAT . Place Files: Put your .pkg files in the root of the drive.
The Ultimate Guide to PS3 to PS4 PKG Install: What You Need to Know ps3 to ps4 pkg install
On your jailbroken PS4, navigate to Settings > Debug Settings > Package Installer . If you are looking for general (not converting