First task with the car still on the ground, in gear handbrake on was to remove the hub nut.
You'll see it's been 'staked' to prevent it coming off at speed (which would be bad).
I chose to use a hammer and sharp punch to bend the stakes back out on the hub nut to some degree; don't bother trying to remove them all the way, that would be difficult.
Then using a sturdy breaker bar to increase leverage and remove the hub nut.
Don't underestimate how tight this may be, use physics! a nice long bar; slip a piece of metal pipe or scaffolding over it if you need to and then stand on it- it will come off.
If you thought you could save a few quid by re-staking the old hub nut (shame on you!) then take a look at it now it's off and realise you should have got one whilst you were in FIAT! and yes I did get one beforehand.
Untighten each of your wheel nuts
Now chock the back wheel well (particularly if your handbrake is poor)
put into neutral and jack her up.
Remove the wheel.
Place on axle stands, - work safely.
There's anothe guide here that describes how to change (and therefore remove which is what we want now) the gearbox oil.
Refer to that, but basically you want your 12mm allen key and undo the nut at the back of the gearbox.
Now then, when I did this job I thought (being a pessimist) that my inner driveshaft boot was so wet with oil, that clearly it had leaked it all out of the gearbox and there wouldn't be much in there.
(Unlike most cars this boot acts as the gearbox oil seal)
So I placed my oil tray more or less underneath the hole as I removed the plug.
THEN, the pressure of 2 and whatever litres of stinking EP gear oil that in fact hadn't left the car; exiting a hole on the side of the gearbox pushed the gear oil out in a lovely geometric arc that terminated about 8 inches away from the farthest side of my 'oil catcher'.:bang:
Remember this sentence and learn from my experience, unless of course you are changing an obviously split boot and you definately HAVE lost most of your oil.
At this point it really was apparrent that the boot probably didn't need to be changed, but we decided to press on all the same!
You should now be at this stage