This is my first try to change oil in my C240. I purchased a oil extraction kit (I do not think there is a oil drain plug) and used it successfully on my daughters M320. I tried to insert drain line into oil fill and could not get it into the oil pan. Does the top part of the oil fill opening come off? Do you drain from the oil filter? Thanks for your help.

 

Never mind, I found a smaller diameter suction tubeand went into the dip stick line.

 

Why not just use the drain plug you, its faster and you get more oil out.