Adjusted inside the car under the flap behind centre console - really easy.
Don't go too tight, or the lever will be unnecessarily difficult to pull up. It only needs to be tight enough to pull the lever down onto the switch (when released). FIAT themselves say in the handbook that four clicks might be appropriate in some conditions and seven or eight clicks in other conditions (on a slope etc.). Gone are the days when you were only allowed a certain number of clicks to pass an MOT.