Hi Chip,
Replacing the line cord on a vintage radio is a fairly straightforward process, assuming you have basic mechanical and soldering skills. Generally speaking, just attach the new cord at the same points as the old.
When replacing a line cord, some restorers like to address the inherent safety issues of the basic "All American 5" hot-chassis design by installing a polarized plug. This is a fairly complex issue, sometimes controversial, but one that you might want to consider if you have little ones about. There is a very good discussion of this subject at
Phil's Old Radios.
All of the above assumes that you do not have one of those "resistance" line cords that were sometimes used on very early radios.
Paula