I did not lift up the clam shell shaped cover. I lifted up the cover from the base of the wiper arm, not the hub which is shaped sort of like a clam shell .
It is made of plastic and the outline can be felt just by tapping it and comparing it with the metal arm of the blade underneith it.
Also note that you can move the arm back and forth manually with the ignition off, with the arm out of the park position and not harm it. I started working the fluid in this way and wiping off the dirt that came out with a rag at first and finnished using some q-tips. Keep working that synthetic ATF in there and leave a generous amount on the shaft.
Good luck lubing up those monoblades folks!!!
Give it a try!
190E 2.6 - 244 000 km