the rear deck ive heard is a b.itch to remove/install the 6x9'*
I just done them in my SSEi and it is tight in the back area, but what I did was pulled on the speaker and mounting ring gently until it poped out of the clips that hold them in.
Upon reinstalling them, you just have to make sure the clips are lined up and then snap the one closest to the seat in first, then the one near the back window. Once you hear it snap in, you know you got it.
It took a few tries, but it was much easier than trying to remove the speaker screws while the speakers are in the rear deck.