Dell Chromebook 11-3120 Bottom Base Cover Replacement

Flip the device over so the bottom is facing up

Remove the 7 visible Philips screws from the device's bottom cover

Insert a thin prying tool into the front (facing the user) corner between the rubber bumper and the plastic case to pop several latches.

Starting from the partially-opened corner, pull the case away from the device in a hinging motion. I rotated the computer so that the opened corner faced me in the image.