不费吹灰之力

bù fèi chuī huī zhī lì

as easy as blowing off dust

effortless; with ease

不

bù

no; not so

费

fèi

to cost

吹

chuī

to blow

灰

huī

ash

之

zhī

(possessive particle, literary equivalent of 的[de5])

力

lì

power