How do you download am NC program from a computer to a Hardinge VMC800 Machine Center

Hello

My shop has a Hardinge VMC800II machining center with a Fanuc Series 0-MD Controller that we bought new 20 years ago. We have had some personnel changes since then and I have been tasked with figuring out how to down load new programs from a PC to this controller. The main part I'm unsure about is what buttons to push on the controller to have it ready to receive the program. Any and all help is greatly appreciated.

Best Regards
Frank