Well, you have to push the rear seat bottom cushion back hard while you lift up to pop the rear seat bottom out. I run the front seats all the way forward, then crouch on the rear floor facing the rear seat bottom and use my leg(*) against the rear seat cushion to push the seat bottom towards the back of the car while I lift up on it with my hands. Once the bench is out you will see that the bottom of the rear seat back is secured by two speed nuts near each door, and by the seat belt nuts in the middle. There may also be a couple of plastic bolts in the seat back from the trunk side if I remember rightly. Once you remove these, as Dame said, you lift the seat back up out of a slot on each side to remove it. You will now see several more plastic bolts, maybe 3, that you will need to remove if you want to remove the carpeted "parcel shelf" or filler panel between the seat back and rear window. Tease the seat belts out of the plastic guides on each side, then remove the two plastic trim pieces on the "c" pillars, or sail panels. These are held by two plastic push bolts on each side. You want to tease these out so that you don't break the plastic slot in the molding that holds the plastic bolt. Lift up the panel and disconnect the speaker wiring and pull the panel out. Now you can remove the speakers and clean or change the carpet or whatever. If you break some of the plastic push fasteners, you can get more at most auto parts stores. Try not to lose track of the little styrofoam filler blocks that serve to position the panel on each side. If they come off, glue them back before you replace the panel to get it to sit right.
Hope this helps.