Removing ALL background images?

I had a partner that did all of the development work for my typefaces in the past, but now I’m learning this end of type design so he sent me all of the files he created in Glyphs of my old typefaces. The trouble is, that he used background images when constructing the fonts, so I have to literally close hundreds of pop-ups that say:

“Missing Image - There is a background image defined, but the image file could not be found”

Is there a way to batch clear ALL of the background images? I found some threads from 3 years back about this, but the commands/menus have apparently changed and therefore the remedies that once worked no longer do. Is there an easy fix for this?

Take a Look in my scripts repository:

There are a few scripts for images, and also a Delete All.

How do I actually implement a script? I’ve never used them before.

This is explained in the readme. There is also a section in the handbook that describes installing and using scripts.