Thanks Mark. The video does show the correct procedure. But apparently does not work on my I3.
With mine, I can press up as hard (or gently) as I want while also altering the direction slightly. Nothing. I have tried both sides of the I3, same result.
BACKGROUND: My reason for needing to use the smaller "metal key" vice the fob is that when I go to the beach I have to swim with the key on me and the fob is not waterproof. (Can't leave anything on the beach in Hawaii, it "disappears" in seconds).
I have heard from other I3 sources that some covers have fallen off while driving (after removal and re-attachment) since it is equally as difficult to put the cover back in place securely as it is to remove in the first place. So I have purchased another "cover" (un-painted) from the dealer to use for those times that I would go to the beach rather than use my original painted cover, or possibly lose it. (Part # 51-21-7-379-775/776 (door cap)). $30.
Examination of the inside of the "new" cover while inserting the key was somewhat helpful in discovering how the cover attachment is supposed to work. It seems simple. The insertion of the metal key from the bottom slightly moves a plastic strut inside the cover to free the cover (supposedly).
So this morning I tried again. After about 20 minutes of everything short of using a hammer to force the key upwards in the slot, the drivers side finally did come loose. Unfortunately there was absolutely no clue as to what exact movement "released" it. Then I did use the metal key to manually successfully lock/unlock the I3 as expected. But then it was another 20-30 minutes of rather increasingly frantic experimenting with attempting to re-attach the cover back on to the handle without any success. Finally in utter frustration I hit the cover squarely with my fist and it "snapped" into place. Not a very sophisticated method, but the only thing that worked.
Needless to say, repeating the above methodology while at the beach parking lot does not seem to be a viable solution.
Asking at the dealership has not been too successful but I will try again. Any other ideas?