Here's another hint that I found on my own car. According to the instructions in the service manual, you can remove the headlight covers by removing the covers and screws that hold them in. I found that by removing those screws, the covers could not be removed entirely; the covers could be lifted up and forward, but the lower front lip of the covers could not clear the housing unless you removed the screws to loosen the headlight housing units themselves. If you're just looking for access to the adjustment screws, then just plan on lifting the covers up and forward, and don't worry about removing them entirely.