Grab the edge of the panel near the middle on the inside along the carpet, and just pull straight up. It'll be a pain, but you can do it. I swapped all mine for the K7 plates, and it felt like they would break, but you'll be fine. Just pull straight up.
There will be a plug, so don't like rip it straight up and run away with it. Disconnect the plug and there should be access to the bulb.
Not sure what size it is, but I know its in there.