W164 Door handle replacement with keyless entry
 

My wife's 2010 ML350 4MATIC has keyless entry. The driver's door handle no longer unlocks when I touch it, and the button does not lock it when pressed. It responds normally to the remote. The other three doors work just fine locking or unlocking.

I found a YouTube video for removing and replacing the handle, and it looks pretty easy. The example handle in the video was not keyless entry/touch-sensitive. What, if anything, does keyless entry add to the task? Extra steps? Extra wires?

I'd rather know ahead of time before I take my wife's car out of service.

Thanks!
Tom