how to change power steering fluid

how do you change the power steering fluid? can u take all the fluid out with a turkey baster? or will air get in and mess it up? take off the return hose and let it leak out? but how does that work. please help. the reason im changing is because the oil is so black

What I did was unplugged the bottom hose and routed it to a pan, started the car and let the oil drain out.