As ramrod said, you need to remove the rear seat. Cushion comes out first, then seat back. Then you'll need to remove the rear headrests (and speakers if there are any). The shelf substrate is held in with a few clips (they usually turn to chalk as well) that go into the child seat top tether anchor points. Once you get the shelf out, you can remove the seatbelt covers. IIRC it's a bit tricky to get the seat belt out through the slot, and there's a metal clip that holds the two sides of the join in the seat belt cover flush with each other. It'll probably become apparent when you see it. The rear seat cushion (and back) are somewhat of a pain to remove. If you can't find instructions online, let me know.
