I have downloaded and saved the manual, there is a section for interior trim sec. 9-17 pages 9 and 10. This gives you the info to remove the rear panels.
http://www.floptical.net/mazda/service_web/ here is the website. I just replaced my rear speakers about a month ago. Here are the steps involved, but it is obviously easier with pictures. seeing the tabs and clips helps as well as having a trim removal tool for poping the clips loose around the door panels. Hope this helps you out!
REAR DOOR TRIM REMOVAL/INSTALLATION 1. Disconnect the negative battery cable if equipped with power win 2. Remove the regulator handle if equipped. 3. Insert a tape-wrapped fastener remover under the pull-handle cover, and disengage tab A. 4. Insert a tape-wrapped flathead screwdriver into the access hole under the forward pull-handle cover, and remove the pull-handle cover by pulling it upward and diagonally while pushing clip B. 5. Remove the screws and fasteners.
6. Disengage clips C using a fastener remover.
7. Pull the rear door trim upward, then disengage
pins D from the body.
8. Disconnect the power window sub switch
connector if equipped.
9. Remove the inner handle from the rear door trim.
10. Install in the reverse order of removal.
