I just did the front doors today, and the rear are similar. ok
1:drink a beer, Ya are gonna hear some popping, and plastic cruching noise. dont be frightened
2: remove the door handel opener bezel. Use a screwdriver (round edges) and gentley pry the front out. the rear will follow. now set the bezel aside
3: the dealer manual sayes to use a GM tool called the J36796 clip zip tool. whatever the hell that is, I use a long screwdriver myself. Pry slowley underneath there and use the leverage fulcurm power of the screwdriver to POP out the plastic fastners.
4: work your way around on all sides ( dont fret about the top) then grap the door handel and wiggle it upwards till the panel comes off
vola your done!
you will proball break some of the plastic fastners, unfortunally they are usually GM spfific and you got to go to a dealer and blow $5 on $.39 worth of parts.
when reinstalling use some needle nose plyers and POP out the metal clips that were in the center of the door trim. then put the metal clips on the door itself.
by doing this to reinstall you do NOT have to slide the door trim downwards. Instead line up the panel and give it a good SMACK all the way around.
It takes some balls to remove door panels, they are tougher than you think. Just work it thought youll figure it out