should be in the manual. and what part of it stopped working? first thing i'd do is turn the car on, turn the AC on, go under the hood and see if the clutch is kicking in on the compressor. and while you're under there, just look around for loose connections before you go on taking stuff apart.
if the clutch is engaging but is doing it many times on and off you may be low on refrigerant, in which case you may want to take it to a shop so they can look for a leak because the car is way too new to need a charge.
if the compressor is not kicking in at all there could be an electrical problem. and depending on what equipment you have you may be able to diagnose this problem yourself. but if it is part of a CAN/BUS network you may need a scan tool
