Chosen Solution
I removed the aluminum support bar that is transverse to the bottom of the keyboard. This bar passes over the open slot that is near the middle of the black plastic back cover that is glued around the keyboard periphery. I removed the black keyboard cover to access the bottom of the keyboard, which I then vacuumed away the dust and cat hairs. What I failed to observe was if there was a part connecting the keyboard & the support bar that fit through the slot on the black plastic. Is there a part there? What does it look like?
See if the pictures in steps #41 - 44 of this guide show you what you need: MacBook Pro 17" Unibody Upper Case Replacement
