First off, there are no 5"ers in the car(front woofers and rear coaxs are 6.5"). Here you go(thru first hand experience):
1. Remove rear seat bottoms, there are 2 pull handles underneath.
2. You will see 2 bolts holding the rear seat backs in place. Remove these.
3. There are 2 screws at the rear corners just below the rear deck. Remove these.
4. There are 2 screws at the base of the panel just behind the doorway. One is a Torqs, the other is a weird plastic phillips one. It will not come all the way out. It loosens, then you pull it out(it has a clip on it).
5. Start from the rear and just pop it off the clips.
I forget if you have to remove the seat belt bolt and the seat and door trim to get this rear panel off. I had all that removed prior to removing the rear panel.