Replacing the stereo system in your Pontiac Grand Prix starts with removing the old speakers and replacing them. The speakers are behind the back seat and can be accessed through the trunk. For ease of mounting the new speakers, make sure that they are the same size as the old ones. It’s useful to take the stock speaker to the audio store to match it up for a perfect fit.
Tools Used: Tools, Phillips-head screwdriver
Get the Rear Speakers Out: Open the trunk to access the speakers. The speakers are located just behind the back seat but can only be accessed through the trunk. Detach the wiring harness from each speaker. Simply pull the connector away from the speaker. Locate the screws holding each speaker up. There will be a screw at each corner of the speaker. Remove the screws, with a Phillips-head screwdriver. Remove the speakers.
Tips & Warnings: The number and type of screws may vary by model and year.