If you're talking about the 5CD changer in the upper dash compartment,then to remove it completely you just remove the upper dashboard liner, I think 3 screws, then unplug the multiplug in the back of the CD changer as you pull out the whole top glovebox liner, stow the cable out of the way and pick up a non-changer upper glovebox liner from FIAT. If you want to sell the unit on, there is a procedure in the maual to de-code it from the Dash unit so it can be used in other cars. Also if you are selling it on, you'll need to pull out the head unit and unplug the other end of the connecting cable to sell with the CD changer, and glovebox liner.

Why do you want to remove it?

If you are only after removing it to repair it or something similar, you can get it out of the cage it is held into the glovebox in by using 2 U shaped removal keys available from Halford for a couple of quid.