You'll need drawings. Interior panels are known to have tricky little clip, hidden fasyeners, and such like that. You could get a manual through the dealer, buy one online, or perhaps access drawings through a Rav4 owners' forum. With some searching, I found a path to the design drawings for my Scion, and I also found tips on Scion club forums. It'll take a bit of research onn your part.
You could pull up the carpet and padding and put second Skin on the floorpans, then reinstall the padding and carpeting. It might help enough for your tastes.