Fold the left rear set down, open the cover you mentioned then there are two screws that need to be removed. One is at the top left and is visible, the other is at the top right behind another cover that hides the emergency pull release for the gas cap. They are torx head screws, #5 if I remember correctly. Once you have the screws out you can insert a screwdriver blade (or better yet a plastic trim tool) and pry up the edge of the panel near the bottom left corner. There are latches that will release quite easily. Once you have two or three released you can get your fingers under the panel and work your way around and lift the entire panel off. It sounds daunting but it is actually quite easy once you find those two screws.
2018 Molten Silver Pacifica Hybrid Limited purchased Nov 30, 2017.