Thanks for your replies... the 6mm bow latch cylinder release screw is under the trunk lid at an awkward angle ...it is what opens the tonneau
The 10mm special tool (or wrench in my case) locks the tonneau in place once it is lowered by turning the lock toward the driver side of vehicle

MY problem lies in the bow latch cylinder release accessed by opening the trunk ...it is turned counterclockwise to release the tonneau

I have turned it clockwise ...heard (and watched) the latch release ...the tonneau is locked tight and will not budge

I suspect another locking mechanism is preventing me from raising the tonneau to raise the top

We did all the standard procedures to reset the top , etc before deciding that manually lowering and raising the top will do unit we find a mechanic we are confident knows this vehicle better than we do