How to edit Symbolic Links in OS X?
Got it!  Turns out ln is the answer after all, but I had an error in my path.

Here is a functional command line for anyone who might need to edit a symlink "in place" in the future:

ln -f -s /path/to/new/location/of/original /path/to/location/of/broken/symlink/

Notice that you're not actually pointing all the way to the broken symlink itself, but to the directory that contains the broken symlink.  This assumes that the expected name of the symlink, is identical to the original name of the linked item.

This is of course for fixing a single link, but from here I can imagine it wouldn't be overly difficult to script a solution that applied something like this recursively.