How do you install rear speakers to 99 regal?

To install rear speakers in a 1999 Buick Regal, first, remove the rear seat and any necessary trim panels to access the speaker mounts. Disconnect the old speakers if present, then connect the new speakers to the wiring harness, ensuring proper polarity. Secure the speakers in place and reassemble the trim and seat. Finally, test the speakers to ensure they are functioning correctly.