I am not aware of a step-by-step for a drain and refill. However, a lot of us just used a turkey baster to remove as much of the old fluid as possible right out of the reservoir. This is the quick and easy way to refresh the power steering system. Once it is empty, fill it up with fresh ATF. This will give you about 75% new fluid as some old fluid will stay in the rack and lines. After a week of driving, repeat the procedure of drawing out the ATF and once again fill it with fresh, quality ATF. Now you have replaced 95%+ of the fluid and didn't have to dismantle anything to do it other than unscrewing the reservoir cap.
This takes only 5 minutes and the baster will cost about $2 at the grocery store.
Disclaimer: DO NOT BASTE A TURKEY WITH THIS BASTER! THROW IT AWAY
