Thats the problem with the turkey baster method, is that you are always diluting old fluid with new fluid, but never fully getting rid of all the old fluid. So after you do it once, technically the next time you are throwing out good fluid that has mixed with old fluid. As you progress you are throwing out more and more good fluid to get rid of a fraction of the old.
Here is what i did and worked perfect, and this will fully remove all old fluid as a 'chunk' (for the most part) and replace with all new. First off don't do it while its running, the pump sucks in fluid FAST and there is no way you will be able to pour the fluid in fast enough to make up for it.
Get the front tires in the air. Suck the reservoir as dry as you can w/ a turkey baster. Take the lower pressure line (after the steering rack going back into the reservoir) and aim that into a oil drain pan sized container or 5 gallon bucket. For mine, b/c the hose was too short, i 'sleeved' over it with rubber tubing, which then ran into the bucket. Then plug up the part of the reservoir that, that hose would plug into. what i did for that was used a piece of double folder over plastic bag and a rubber band, you can use a tapered rubber plug ect. Now fill the reservoir up to the top and just turn the steering wheel back and forth from full lock to full lock. (since its up in the air w/ little resistance you can just turn the wheel through the open window so you dont have to keep going in and out of the truck, unless of course you have a partner

) Every turn or so top off the fluid level. The old fluid will be belching out into the bucket and after about 3 quarts or so (i forget exactly, buy more than you need just return the rest, i used about 5 total i think) you will see the fluid start getting much lighter and more clear. i ran through another quart or so until it came out looking like new. Then i just turned the wheel lock to lock enough to drop the fluid level to the bottom of the reservour. Remove you're plug, reattach the return line, and fill to proper level.
I did this a few months ago on my 98' i bought it with 130k on it and did this around 140k. I highly doubt the fluid was ever changed it looked like well used ATF. The new fluid that went in looked (and still does) like new brake fluid!
And please properly dispose of the old fluid
