Hello there

I have a PowerPoint document that it’s modifier (he’s not even it’s author) used a textbox in all of the slides & put his email address there!
Slides are a lot & I can’t simple remove them one by one it’s a waste of time.
Can anyone plz help me how can I remove them all at once? I saw someone did it to a repeated picture using “Macros” but I’m not expert how to do.
Your help would be appreciated, thx.