When I decided to change the head unit that came with my FTO I turned to every FTOs best information source, the internet. Sadly, there is little about on how to change the head unit, which is something that most of us want to do at some point. Hopefully this worst-case scenario will help a few people
When I set about to change my stereo I had a few problems to face. 1) The centre console centre piece was cracked nearly from side to side just in front of the gear-stick. 2) Because of this crack I couldn't risk undoing the screws that hold the gearstick surround on to release the centre piece. 3) I was winging it!
At least the 3rd one isn't an issue for you, and hopefully it will prevent 1, and therefore 2

The stereos in the FTOs are fitted in a way that is different from any I've ever dealt with, so possibly to you too. The stereo is screwed to a large bracket on either side, these brackets are screwed to the centre console, and hidden behind the centre section of the centre console

You will need:

A thin bladed flat screwdriver

A fairly chunky philips screwdriver

A wire coat hanger

We start by removing the centre piece. As I said earlier, I cracked mine on my first go and had to leave it a week before I tried again for fear of breaking it completely. If you follow my instructions you should be able to remove it without this happening to you. I managed with one already cracked Start by prying up the centre piece at the point nearest the handbrake. Try to do this with your fingers to save marking it. Once you have something you can get a grip on, work your way round on both sides. There are 2 clips located just where it straightens out. If it's getting stiff, poke the hanger hook into the largest gap and work it round. Once these two are free (they won't come up a great deal, but if you can see them they are free) stop for a second or two. This is when I cracked mine
The next 2 clips are either side of the ashtry and cigarette lighter. The problem is that the gearstick may cause some resistance. At this point I put some duct tape over my crack to strengthen it while it was being pulled and twisted all over the place Start by removing the ashtray and cigarette lighter. Not the wells either of them sit in, just what comes out easily. Start working the coat hanger hook up which ever side is proving the easiest. This might be a bit tricky, but be patient, and use the flat screwdriver in bits too tight for the hanger. The second side should be easier, but remember to put the flat bladed screwdriver into a gap on the other side so the clip doesn't slip back into place
Unless you've done this before, you'll probably be surprised it hasn't fallen out now. There's 2 more hooks at the top, but these can only come free with a bit of wiggling, and lifting the bottom end up If your centre piece is A piece still, you might want to brave undoing the screws on the underside that hold 2 clips in place, that hold the gearstick surround to the centre piece If you have been unlucky like me and had to leave the gearstick surround attached, and especially if you have a trinket tray, you will need to do a lot of wiggling to get the centre piece to swiwel round 90 degrees
You should now be able to see the 4 screws around the stereo. Take these out and keep them safe in the cupholder. Pull the stereo towards you, tilting it up as much as you can. Disconnect the wires and check that they are compatible with your new head unit. If you have changed model, or the existing wiring harness in the car is not compatible with your new head unit it's best to find out now. Halfords and Mitsubishi do a number of convertors, and there are re-wiring instructions on Funky5s web-site. If your wires are compatible, you should be able to pull your old head unit out. Half the job done!
Take your old and new head units and the philips screwdriver to somewhere easier to work. Remove one of the side brackets, and place both stereos on their sides next to each other. This should allow you to more acuratly attach the plate to the new stereo so that it sits forward the correct amount Once you've done both brackets it's time to put the new head unit in. Connect the wires, wiggle the head unit into place, screw the point screws for the brackets in, do a lot more fiddling with the centre piece to get it back round 90 degrees, put the top in first so that the 2 clips that go under the AC go in, work your way slowly down pressing the clips into place
Voila. Job done