The rear speaker covers on a 2005 Toyota Camry are secured to the rear deck by a screw under the square plastic covers on the sides of the speaker's cover frame. The rear speaker covers don't need to be installed at all times, but to replace the speaker you need to remove them. The only propose that the covers serve is to conceal the metal frame and screw on the speakers themselves.
Open the rear doors and get into the backseat. Face the rear deck where the speakers are mounted and locate the plastic cover on the side of each speaker cover.
Pull up on the cover to remove it from the frame. The cover will be connected to the frame by a thin plastic tab and will fold out when you pull up on the cover.
Remove the screws from the frame using the Phillips head screwdriver. Lift up on the edges of the speaker covers and pull the covers off of the frame.
