Terms for subject General containing difficult part

English	Russian
he is a difficult man to part from his cash	из него не выжмешь и гроша
it is a difficult part to sing	эту партию трудно петь
it is a difficult part to sing	эту партию трудно спеть
the most difficult part is done	самое трудное сделано
the most difficult part is done	самое уже позади