the belt is easy.
when youre done, DO NOT take your AC to be serviced by anyone but a Alfa mechanic who worked at the dealership. the Alfa AC unit only needs some freeze12, some Esther100 (oil) and a few schrader-valves to work again. no reciever/dryer, no new compressor.
mine sat unused for 5 years with no belt, and is cold as can be now. costed me 80$