Scripting Keynote UT

Attempting to remove effects from images on Keynote slides. In the application UI, there is a Change button on the right. When you click Change, you select the new effect or none. I would like to do this with Applescript. I have worked out how to click the 'Change" button, but not how to click into the list and select the desired item. I have a script that gathers all UI elements, but it’s not clear which element needs to be changed.

Please post the code you already have.

Also maybe a screen capture of the change button, that I can’t seem to find