Removing Graphic Interface of Linux Mint

[RedWagon]

o.O
A few questions:
Why do you want to remove the graphical interface? What are you trying to accomplish?

You can still get all the the functions of the command through terminal in the GUI, but if you remove X11, you can't get any of the GUI functions back wihtout re-installing everything. If you really want a command line only OS for a server you should probably pick a different distro, though if you're a noob, you will be completely lost.

[RedWagon]

As I said in my other posts, for what you are trying to do, you will probably be much better off with a different server based distro.

[AK Dave]

I have to prepare an exam consisting in making minimal a "normal" linux distribution keeping routing and parental control functions.

You want a simple command-line linux distro. The linux kernel includes iptables, which can be configured to give you all the parental web-nanny blocking you might desire. Problem solved, in a nutshell.

So you're going to remove xserver, everything associated with xserver or xorg, everything that depends on xserver, everything that runs on X including all of Gnome, and everything that depends on something that runs on xserver. Plus every program that starts with a g or a k.