I've got the engine cover and air boxes off, how does the plastic air tube/ecu at the back of the engine pop off? I can't find anything to unbolt and I don't want to pull up too hard and break something. Not sure where to go from here. I did a search, found a DIY, but not for the C63.

Thank you!

You don't have to remove the engine cover or the airbox covers. The ECU is beneath the a/c unit in the upper left hand corner of the engine bay. There are three clips on the top of it which you flip open. Then, lift up the curved box that has to do with the a/c system somehow. Underneath that is the ECU. I don't know how you take it out though.

I got it. Thanks for the assistance!

You're welcome!