A VPN and server right access

Hi i have been trying to figure this out for a long time. I am sure alot of you techs probably know bout this, but its very confusing to me and im kind of a green horn at this. But i need to know how to install a VPC to gain wide area network access to private servers from my personal network. The client is allowing me access to their private server which holds a data center, its bout 10,000 miles away but with an installed VPN and remote access, he told me i am able to access his server. He already has a VPN ready and connected for use. I just need to install a VPC to use their data bank and transfer, copy, files to my personal network. My current connection and dl has been capped to a very low speed, so this is why this user is allowing me access to their server. But in order to do so i need to be able to install and configure a VPC for remote access. I have tried finding tutorials online, but most of them are complicated and some how my computer just will not accept a VPC install. I don't even know if im using the right terminology for this, but what im basically trying to do and what this guy said i can do is hook up a VPC, using a FTP

What does the client recommend? Surely that are already using a VPC as you call it, so use the same one.