"David Combs" wrote:

I stupidly zipped up my coat when I hadn't perfectly
lined-up the bottom ends of the two sides.

(Actually, it's been acting up a bit (getting old?) and
the "male" left side bottom-end doesn't so easily and surely slip into
the matching "female" right side.)

Anyway, it's zipped up a couple of inches, but off by 3 or so
"notches" (due to that male-female problem).

Any idea on how to get it unzipped?

Zippers wear out, sometimes before the coat does.

You can buy a new zipper, and sew it onto the coat.

Jon