[jpeter6981]

The "circular" piece in the center of the pad pulls down (which will then allow you to push the pad into place on the frame) Then push the "circular" piece back up to lock it into place. Be careful though... it is pretty easy to break that center piece. Also, when reinstalling your protective covers... make sure they both fit properly under the tabs that are sticking out from either side of the pad, or, you will just break those off as well.

 

[jpeter6981]

I just looked up that part number.. that seems to be a side mount jack pad. Is this what you have? This is for the front, center:

 

[jpeter6981]

That pad in the picture that you posted is for the side jacking points on a W204. The one that I posted is for the center front.

 

[jpeter6981]

Hello Baron. This should be the part number you need: 002-998-06-50

There are all kinds of them on Ebay / Amazon / dealer sites (both MB and aftermarket)