There are 2 recommended methods of uploading files to VPS/Dedicated servers:
WinSCP (for windows users only)
You can download WinSCP here:
http://winscp.net/eng/download.php
To create a connection to your server in WinSCP:
1) Add your server IP address into the Hostname field
2) Set protocol to be SFTP (this works on port 22)
3) Enter root as your username
4) Enter your root password
SFTP (Using a normal FTP Client such as FileZilla)
Create a new connection in your FTP client:
1) Add your server IP address into the Hostname field
2) Set protocol to be SFTP (this works on port 22)
3) Enter root as your username
4) Enter your root password