Thanks everyone for the help! I did finally get the door panel off. It was the bolt behind the window switch control that I finally got to. I took the speaker out and examined the speakers. The foam portion was coming loose from the exterior rim, so I cleaned the rim where the foam detached from with rubbing alcohol, filled the area with silicone glue, and attached the foam back on the rim. I put the speaker back in and everything sounded fine. It took a little time and effort, but it was worth saving the $650 the Lexus dealership wanted to charge me.