Unless you are very intuitive, you'll need a service manual. However, the basic steps are: 1)Remove rear side wall 2) Remove molding strip above and behind shutter 3) Remove 4 screws holding shutter assembly.
Step 1 requires removing the rear seat and backrest, chrome trim strips at door and window, 3 screws at back side of panel
Step 2 requires a similarly detailed set of removals
Step 3 is the easy part.
Good luck, Bruce