If you simply drain & refill the reservoir that's maybe less than half the fluid. So do it all again every couple days until it stays clean.

You can lift the front of the car (support it good), find a PS hose at a low elevation (cooler tube in front of the radiator??) Open that tube, start the engine, spin the steering lock-to-lock a couple times to empty the system more completely. (It'll squirt out & make a mess.)

Hook it back up & fill it. Leave the wheels still in the air so there's not much load on the system. Start the engine, turn back & forth twice & shut it off. NOW it'll be real foamy so repeat the settling/refilling business again.

Dont leave the engine running any longer than you have to; just long enough to twist the steering wheel back & forth.