Tiny bubbles in the wine, make me feel happy, make me feel fine. (Don Ho song)
Tiny bubbles in the power steering fluid, not so much!

I had a failed CPP 500 steering box, which I replaced with a new one. On the original box, I filled it with PS fluid before the first start up. I didn't do that this time and have frothy PS fluid. Maybe it was my attempt at bleeding that was the problem. With the front end in the air, I started the car – had a leak, shutdown, got that fixed. I added some PS fluid, started the engine, and rotated the steering from lock-to-lock a number of times. I checked the PS fluid, and the fluid was frothy. Drat. I left the cap off the steering pump overnight, and the next afternoon, the bubbles were gone from the measuring stick. I think I did the bleeding wrong, should have rotated the steering with the engine off? Later, after adding some more fluid, I rotated lock-to-lock 10 times with the engine off (and the cap off the PS pump), and the stick was frothy again. What do you advise I do to get rid of the froth (I assume the bubbles will come out of solution with time, but maybe not?), and how to better bleed the PS?
Thanks, Doug