In answer to your question, there are a bunch of push clips which can be removed by simply pulling out the head part and then prying out the base. Also there is a hook at the top part of the side trunk liners which attach to the fuel tank cover (back ot trunk).
The easiest way to remove the CD changer is to remove the 2 bolts holding hte bracket to the base of the boot floor (when you lift up the trunk floor carpet you'll see what I mean).
Once all the push clips, hook & changer are removed the liner can pried out.
Make a note of how the liner is attached to light surrounds and boot lip so that you can reinstall it as it is supposed to be. (I take digital pics when I start to work on a car I'm not familiar with).