Karl no doubt it should get changed every 3 years or so or x ammont of miles, saying all this i have never changed the gear box oil in my van and i have been driving it for 6 years!
its not hard to do it your self, there is a guide on the forum
stephend
What a twa* who puts 27 pounds of petrol in a diesel? derrr
with the fluid you get a spout neck so you can pour it in.Think mine takes 2 litres to fill (according to the data) but have 1 3/4's in so have some spare.
Put 1 ltr in mate you should be fine,but saying that you may not need it all
It would probably be fine if you never changed it. Should'nt really need topping up unless theres a leak somewhere, gearbox dos'nt use oil like an engine.
If you really like to look after your car then its worth changing it, I did on the jtd. Make sure you get the correct oil recomended by Fiat, can make a difference.