Thank you for all of the useful information. My plan is to not remove the tonearm, because I want to do as little tinkering as possible. That's why I want to find a long screwdriver that will fit through the access hole on the deck of the 1249. I want to remove the head shell retainer by removing the screw while the tone arm is attached. Because of arthritis, I would prefer a metric screwdriver with a padded/bigger handle.
If I did want to remove the tonearm tube, however, how would I do that without damaging the pivot settings, etc? I do have the service manual, but am still not clear on the easiest way to remove the tube with no damage.
Again, thank you for your helpful insights/advice.