It seems that the easist projects take the most time
I bought a concourse antenna with a screw-in telescoping mast to replace my one piece antenna. The existing antenna has a folding nut and the base easily slips trhough the opening in the front fender. The lead is routed though a rubber grommet in a side wall steel panel (where the fuse box is located)behind the kick panel.
The new antenna has a large base witha knurl that matches the fender opening that won't slip through the fender opening from outside the car - it must be installed from the inside of the fender which does not match the discussion in the service manual - anyone have some tips on how this is done?

Take the splash shield off inside the fender behind the tire

You will have to loosen the inner fender by removing the bolts from inside the wheel well. Then you will be able to intall the antenna from the wheel well. You may not have to remove the inner fender. You may be able to move it out of the way so you can get your hand in there to intall the antenna. I don't remember if I removed it or not on my '66.

Thanks for the help! When I took off the bolts around the panel it swung away far enough to insert my arm and easily install it.