you pop out the circles and then on the inside there will be a little rip cord you have to turn just slightly to pop out the hole, otherwise the whole pillar pops out. I've taken my rear deck apart many times, the only thing you need to watch for is when pulling the rear deck out be careful not to bend it to much or you may leave a little crease line in it.
to do it right you need to pull the back of the rear seat
then you need to remove at least one of the side trim pannels, the head rests and the plastic piece behind the rear seat to get the rear deck out. I've had mine out and recovered in leather. It can be a chore.......... and he was right the cover has to be removed to get the rear speakers out.
I drive a 2006 pontiac pursuit GT. The things I'm talking about are right angle triangle shaped and there is one on each side and in the middle there is a plastic circle. Is it worth it to put new 3 way pioneer speakerS? or are the stockers better?