How do you install rear speakers in 2000 Mazda Protege?

There are three huge bolts covered with a trip peace rising out of the rear deck, the middle of which rotates. Pry the trim of the bolts to expose the head of the bolts. Use a wrench to remove the bolts.

Using a flat blade screwdriver, gently pry up the housing for the rear shelf brake light to release the clips. Disconnect the wire to the bult and remove the brake light housing.

Bend the rear seats forward and remove the two clips that hold the front of the rear deck to frame of the car. Lift up the rear deck gently to break loose the clips that hold the rear shelf to the horizontal frame: you will need to go into the trunk and squeeze on these clips to help it come through the hole. When the cardboard shelf clears the frame, slide it forward to expose the speakers.

Remove the stock speakers (which by the way, are a piece of junk, Mazda and all auto manufactures should be ashamed) and install your new speakers. Replace rear shelf and brake light housing and enjoy.