U pull the pan. I believe it's six t30 torax with spacers that actually put pressure on the pan. Take the back two out, loosen the front two a little bit. Then slowly take the middle ones out. Just that will let the fluid out slow so you are not covered in it. Take the pan down once the fluid slows. Empty rest of fluid from pan. The fluid changes is the same as any other. Drain, replace filter, put pan back on, fill back up. I put a gallon of new fluid in the trans then start the vehicle up. Then add about another gallon then start checking the fluid level. Not every trans is the same amount so don't stick the whole second gallon it at once. About three quarters then check. Some Mercedes transmission do not come with a dip stick and you would have to buy a special one off the internet or parts store. If you actually want to flush it so you can get all the fluid out, you will have to bring it to the dealer or trans shop.