I have the service manual. It's not very clear as to how the panel comes off. I am also using the instructions from the FAQ...but, nevermind, I found the problem..First, there are no 10mm bolts as described in the FAQ. My '91 had two phillips head screws that needed to be removed (which I had already removed). What I didn't realize was that the panel is also held in place with four clips (so it needs to be gently pulled off). Thanks anyway.
BTW - The service manual (page 23-238 vol.2), doesn't even mention removal of the lower panel when replacing the foot well bass speaker. It is definitely an easier job when the panel is out of the way.