SSH is fast and secure method than ftp to access the server and transfer the data from one server to another. Transfer of the data by ftp take more time in case of large data files and involve some
security threat. Hackers may exploit ftp password easily.
In another case you can access the server through ssh using
PuTTY
Download it on your local machine and access your both the servers.
For data transfer:
Rsync is use to transfer the data from one server to another. It is one of the fast file copying tool which can copy locally, to/from another host over any remote shell, or to/from a remote rsync daemon.
Please feel free to open ticket if you want to migrate data from old server to vps