First time with xbian

[Krassegrand]

I am trying to install xbian to my 4GB memory card!
I have extracted the files to the micro card and now I don't know what to do!
On the site it says

Linux

Download here, extract the file and run.

And in the read me file it says
Open a terminal and run the following commands:

chmod +x XBian-installer
sudo ./XBian-installer


shall I do this while standing in the memory card?

Jörgen