The answer for anyone who cares is '2 thin screwdrivers pushed in all the way, then push both outwards at the same time - left pivots left, right to right. Whats left is a 1/16 x 1/2 x 1 inch white base , all of the black clip releases. Its also possible to push too hard and break off the clip base,...

Upper righthand face of cem; there is one on the right side as well

Advice appreciated