there are 3 plastic "buttons" along the front edge that have to come out.
then there are 3 or 4 push connectors that extend into the trunk.
on mine, i opened the trunk so i could pinch them from the bottom and push them up.
if you look up in your trunk you should be able to identify them fairly easily.
once the package tray is at least loose, you should be able to pull/twist/flex it out from under the C pillars w/o removing them.
the package tray is pretty flexible. just don't bend it so hard you crease it and you should be fine.
let me know if you need more info. i have pics of the bottom of mine showing the push connectors.