Ok... everything has an answer including this!
What I did was to sell a similar item using the listing I wanted to replace the pictures on.
I deleted the old pics and selected the new uploads I preferred to use.
Then I click "Preview" and copied the whole description.
Revise active auction-
Select ALL in description set on Standard and pasted the corrected description. save changes
GROOVY! It worked!
It's a bit of song and dance, but it can be done.