If I were you, before even starting the engine and circulating the fluid, I'd get a turkey baster and remove what you can. Then remove the hoses and drain the pump reservoir, then do a PS flush as described elsewhere on this forum. At this point, you don't have brake fluid in your steering rack, and you should endeavor to keep it that way. Brake fluid is nasty stuff, and the pump and rack are pretty particular as to what you put in them...
