You will have to remove the radio. That is not difficult. The speaker grill does come off but only from the bottom. The speaker itself is held in place by four screws (as I recall) that you access from the bottom. You must remove the heater plenum (the cardboard to the left of the heater assembly) to remove the radio. Unhook the power, speaker, and antenna wires, remove the cap screws holding the mounting brackets on the side of the radio, pull the volume and tuning knobs off the front, remove the two nuts holding the radio in the dash (behind the knobs), and the radio will practically fall out of the dash.
Thanks, I was afraid the radio would have to be removed mainly because I just had someone remove the radio and I sent it off for repairs and just had it re-installed without checking the speaker. The joys of restoring an old car. With your instructions I believe I will do it this time myself. Thanks again, Wayne Jones, Georgia.