The most wasteful and inefficient method. I pumped out the old fluid from the top using a $7 hand pump, added more fluid, pumped it out, repeat, turn the wheel, pump it out, add some etc. until the fluid was clean. I used an entire can of fluid, $23.99 at Autozone.

Yeah, that's sort of how I plan to do it. I think two drain & fills will be good enough for me since it is such a big reservoir. That's $75 in fluid alone.