The intent Mercedesshop is to help each other out and share our experiences. It is not meant to give step-by-step instructions for someone looking for specific instructions - that is what the "search" feature is for.
I have done the transmission fluid change on a 722.6 transmission and did a write-up:
http://www.peachparts.com/shopforum/showthread.php?t=48798&highlight=722.6+transmission.
I advise that you do not take on this job unless you have successfully done a trans fluid change before and that as Brian pointed out the temperature of the fluid is critical to accurately measure the fluid level.
Good luck.