ποίει ὅ, τι ἂν ΒΟΥΛΗΙ · ΕΣ ΚΟΡΑΚΑΣ ἐρρόντων οἱ ἄλλοι
Literally, "Do what you like; let the others go to the crows." There's no equivalent in ancient Greek to the idiom you use. For a more exact equivalent, try our English -> Modern Greek Forum. You'll still get Greek letters (for your tattoo, we assume).