Is the power door lock plunger froze?
inside the hole in the door panel should be a rod with the end bent, push the rod rearward or forward I forget.
if the power lock plunger is not frozen it should open the door.
Sometimes a little bit of crud can get into the latching mechanism.. Take a long skinny pressure blowing nozzle to it and try blowing anything that may be stuck in the mechanism....
I have had to replace both outside door handles on my Mustang because they quit working.
Sometimes if you pull up on the outside handle at the very rear of it, and kind of hold the front portion of the handle so it stays level, the door might pop open, that is assuming the linkage is still hooked up.