Here you will learn how to manage your free vps via SSH under Windows OS. For Linux and Mac OS you should use similar method, besides Putty, you should use native Terminal app.
If your pc is compatible with IPv6, you may connect to SSH via Putty terminal to manage your VPS. (If you do not know if your PC is compatible with IPv6, please check this thread how to configure it: Configure PC for IPv6 )
(You may download free SSH client for Windows - Putty.exe here: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html )
Check your IPv6 Address, you may find it in your Client Area->Servers tab.
Run Putty.exe, enter your full IPv6 address into Hostname field and hit Open.
In most cases you will see Security fingerprint alert, hit: Yes.
Enter your VPS username (mostly it is: root) and your password (you may change it via VPS.ME client area -> Root password section).
Now you're able to fully manage your VPS via SSH.