Thank you all for this amazing post. Viva Internet. I have to admint it took me a few readings as English is my second language. Finally I fixed the issue.
First, I opened with a cloth hanger as specified by rfbqwerty. Had to redo this procedure three times as my wife did push the button manually by mistake. Got tired of it and my last time was yesterday when I decided to open the door panel and installed a new spring to the mechanism. It cost me $4 (canadian dollars) at Lowes.
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Attached are three pictures where you can see the newly installed spring. A picture is worth a thousand words!
Hope it helps!