Light bulb replacement, how can I remove the cover to change out the bulb without taking out the entire headlight?

There is no replaceable low beam bulb in that unit. Under the cover is a control board for the lamp module. The high beam bulb is replaceable as is the turn and park bulb, but the low beam LED is actually part of the headlamp assembly and if the low beam has failed you have to replace the entire lamp assembly.
I would suggest going with an aftermarket unit simply for cost savings as the OE unit is close to $600.00 list. To replace them you have to remove the front bumper cover (or at least move the side you are working on out of the way enough to access the rear screw and the clip underneath. To do that you have to remove the grill first, for that remove the three screws on top, then gently pull the grill straight out to release the clips. Next you need to release the pins and screws that secure the bumper cover to the body. Now reach in and disconnect the electrical connectors. Now go to the grill opening and you will see three push fasteners, those pull out (don't be shocked if they break, the plastic pins all seem to be made of single use plastics, you can get replacements for most of them at a parts store or possibly even at a harbor freight if you look at their item 57671).
Now you can remove the screws that retain the lamp and remove it, then disconnect the electrical wiring. Reverse the process to install the replacement.