If it's the same as the GT 1.9 16v here's how I did it.
1. Remove top engine cover
2. Remove battery (usual precuations regaring radio codes)
3. Depending how fussy you are you could undo a lower radiator hose, drain and keep your anti-freeze, personally I couldn't be bothered. I syphoned off as much as I could from the expansion bottle them simply removed the large hose at the front of the 'stat and allowed what was left to fall to the floor.
4. Undo the electrical connector, there's a yellow tab to pull down, still needed a small screwdriver under the connector to gently ease it off, look at the new one to see.
5. There are 4 hoses, 3 of which (on mine) had the one-time hose clips that you snap off with a small screwdriver in the loop, there was one with a screw/nut to release. One of the hoses is tucked away at the top and is only possible to get at once the 'stat has been removed.
6. Undo the 2 fixing bolts into the 'stat housing, have a look at your new one to give an idea where you need to look to find them.
7. Give the face a good clean to remove any debris, install new 'stat in reverse order. Top up anti-freeze, run the engine and check for leaks.
I left mine running for a good few minutes and was dismayed to see the temperature gauge hadn't budged. FFS! However as soon as I took it for a run it started to rise and sat nicely at 90degrees. Next day took it for another drive to pick my daughter up from the train station, not a long trip and the gauge had only reached 70degrees, I sat there for a good 5 minutes ticking over, temp didn't move, however as soon as we started off it reached 90 again and stayed there. Can't say whether this is normal behaviour.
No special tools required, just hose clips and anti-freeze. The very top hose is a pig to get a clip on owing to it being right next to the supplied hose below, the clips I used had a large worm screw and found it difficult to get the orientation right so it didn't foul the hose below or foul the cylinder head when trying to bolt it back on. Have a look at the image below, I've rotated it's more-or-less in the position you'd see it on the car.
Further steps that may be required if you're as disaster prone as me every time you go near the engine bay. Remove battery tray attempting to find thermostat 'O' ring that dropped off when refitting, only to then use the old one as it was nowhere to be seen.
Remove undertray and front bumper to retrieve thermostat bolt that dropped down the hole adjacent to the bonnet release catch.
Good luck with it